Fix bottom bar in CoordinatorLayout

Try this layout :

<?xml version="1.0" encoding="utf-8"?><android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:app="http://schemas.android.com/apk/res-auto"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:id="@+id/container">    <ScrollView        android:layout_width="match_parent"        android:layout_height="match_parent"        android:layout_above="@+id/bottom_navigation"        android:layout_alignParentTop="true">        <LinearLayout            android:layout_width="match_parent"            android:layout_height="wrap_content"            android:orientation="vertical">        <android.support.v7.widget.CardView            xmlns:card_view="http://schemas.android.com/apk/res-auto"            android:id="@+id/card_view"            android:layout_width="match_parent"            android:layout_margin="10dp"            android:layout_height="110dp"            android:padding="15dp"            card_view:cardElevation="2dp"            card_view:cardCornerRadius="4dp">            <TextView                android:layout_width="match_parent"                android:layout_height="match_parent"                android:text="Test" />        </android.support.v7.widget.CardView>        <android.support.v7.widget.CardView            xmlns:card_view="http://schemas.android.com/apk/res-auto"            android:id="@+id/card_view1"            android:layout_width="match_parent"            android:layout_margin="10dp"            android:layout_height="110dp"            android:padding="15dp"            card_view:cardElevation="2dp"            card_view:cardCornerRadius="4dp">            <TextView                android:layout_width="match_parent"                android:layout_height="match_parent"                android:text="Test" />        </android.support.v7.widget.CardView>            <android.support.v7.widget.CardView                xmlns:card_view="http://schemas.android.com/apk/res-auto"                android:id="@+id/card_view3"                android:layout_width="match_parent"                android:layout_margin="10dp"                android:layout_height="110dp"                android:padding="15dp"                card_view:cardElevation="2dp"                card_view:cardCornerRadius="4dp">                <TextView                    android:layout_width="match_parent"                    android:layout_height="match_parent"                    android:text="Test" />            </android.support.v7.widget.CardView>            <android.support.v7.widget.CardView                xmlns:card_view="http://schemas.android.com/apk/res-auto"                android:id="@+id/card_view4"                android:layout_width="match_parent"                android:layout_margin="10dp"                android:layout_height="110dp"                android:padding="15dp"                card_view:cardElevation="2dp"                card_view:cardCornerRadius="4dp">                <TextView                    android:layout_width="match_parent"                    android:layout_height="match_parent"                    android:text="Test" />            </android.support.v7.widget.CardView>            <android.support.v7.widget.CardView                xmlns:card_view="http://schemas.android.com/apk/res-auto"                android:id="@+id/card_view5"                android:layout_width="match_parent"                android:layout_margin="10dp"                android:layout_height="110dp"                android:padding="15dp"                card_view:cardElevation="2dp"                card_view:cardCornerRadius="4dp">                <TextView                    android:layout_width="match_parent"                    android:layout_height="match_parent"                    android:text="Test" />            </android.support.v7.widget.CardView>        </LinearLayout>    </ScrollView>    <RelativeLayout        android:layout_width="match_parent"        android:layout_height="match_parent"        android:layout_gravity="bottom"        android:gravity="bottom">        <android.support.design.widget.BottomNavigationView            android:layout_width="match_parent"            android:layout_height="56dp"            android:layout_weight="1"            android:foregroundGravity="bottom"            android:background="@color/green"            app:itemIconTint="@color/white"            app:itemTextColor="@color/white"            android:id="@+id/bottomnav"            app:menu="@menu/main">        </android.support.design.widget.BottomNavigationView>    </RelativeLayout></android.support.design.widget.CoordinatorLayout>

The best possible solution will be making this kind of hierarchy

<ConstraintLayout>    <CoordinatorLayout>        <AppBarLayout>           <ToolBar>           <TabLayout>        </AppBarLayout>        <Inlude>           Put the Main Content here.        </Include>    </CoordinatorLayout>    Other Widgets that you want to be placed at a fixed position.</ConstraintLayout>

Don't forget to add

app:layout_behavior="@string/appbar_scrolling_view_behavior"

the above line into your included layout parent ViewGroup

Let's have an example of the approach that I am talking about

<?xml version="1.0" encoding="utf-8"?><androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:app="http://schemas.android.com/apk/res-auto"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent">    <androidx.coordinatorlayout.widget.CoordinatorLayout        android:layout_width="match_parent"        android:layout_height="0dp"        app:layout_constraintBottom_toTopOf="@id/container"        app:layout_constraintEnd_toEndOf="parent"        app:layout_constraintStart_toStartOf="parent"        app:layout_constraintTop_toTopOf="parent"        tools:context=".activity.Dashboard">        <com.google.android.material.appbar.AppBarLayout            android:id="@+id/appBarLayout"            android:layout_width="match_parent"            android:layout_height="wrap_content"            android:theme="@style/AppTheme.AppBarOverlay"            app:elevation="0dp"            app:layout_constraintBottom_toTopOf="@+id/container"            app:layout_constraintEnd_toEndOf="parent"            app:layout_constraintStart_toStartOf="parent"            app:layout_constraintTop_toTopOf="parent">            <androidx.appcompat.widget.Toolbar                android:id="@+id/toolbar"                android:layout_width="match_parent"                android:layout_height="?attr/actionBarSize"                android:background="@color/background"                android:elevation="0dp"                app:layout_scrollFlags="scroll|enterAlways|snap"                app:popupTheme="@style/AppTheme.PopupOverlay"                app:titleTextColor="#000000" />            <com.google.android.material.tabs.TabLayout                android:id="@+id/tabLayout"                android:layout_width="wrap_content"                android:layout_height="wrap_content"                app:tabBackground="@color/background"                app:tabIndicatorColor="@color/colorAccent"                app:tabMode="scrollable"                app:tabSelectedTextColor="@color/black"                app:tabTextColor="@color/black" />        </com.google.android.material.appbar.AppBarLayout>        <include            android:id="@+id/include"            layout="@layout/content_main" />    </androidx.coordinatorlayout.widget.CoordinatorLayout>    <RelativeLayout        android:id="@+id/btSend"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_marginRight="@dimen/_50sdp"        android:visibility="gone"        app:layout_constraintBottom_toTopOf="@id/container"        app:layout_constraintEnd_toEndOf="parent"        app:layout_constraintHorizontal_bias="0.5"        app:layout_constraintStart_toEndOf="@+id/btReceive">        <com.google.android.material.floatingactionbutton.FloatingActionButton            android:id="@+id/fbSend"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_marginBottom="@dimen/_30sdp"            android:background="@color/colorAccent"            android:src="@drawable/ic_upload"            app:rippleColor="@color/colorAccent" />        <TextView            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_alignLeft="@id/fbSend"            android:layout_alignRight="@id/fbSend"            android:layout_alignBottom="@id/fbSend"            android:layout_marginBottom="@dimen/_3sdp"            android:elevation="@dimen/_10sdp"            android:gravity="center"            android:text="SEND"            android:textColor="@color/white"            android:textSize="@dimen/_8sdp" />    </RelativeLayout>    <RelativeLayout        android:id="@+id/btReceive"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_marginLeft="@dimen/_50sdp"        android:visibility="gone"        app:layout_constraintBottom_toTopOf="@id/container"        app:layout_constraintEnd_toStartOf="@+id/btSend"        app:layout_constraintHorizontal_bias="0.5"        app:layout_constraintStart_toStartOf="parent">        <com.google.android.material.floatingactionbutton.FloatingActionButton            android:id="@+id/fbReceive"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_marginBottom="@dimen/_30sdp"            android:background="@color/colorAccent"            android:src="@drawable/ic_download"            app:rippleColor="@color/colorAccent" />        <TextView            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_alignLeft="@id/fbReceive"            android:layout_alignRight="@id/fbReceive"            android:layout_alignBottom="@id/fbReceive"            android:layout_marginBottom="@dimen/_3sdp"            android:elevation="@dimen/_10sdp"            android:gravity="center"            android:text="RECEIVE"            android:textColor="@color/white"            android:textSize="@dimen/_8sdp" />    </RelativeLayout>    <androidx.constraintlayout.widget.ConstraintLayout        android:id="@+id/container"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:layout_margin="@dimen/_7sdp"        android:background="@drawable/bottom_bar_corner"        android:padding="@dimen/_5sdp"        app:layout_constraintBottom_toBottomOf="parent"        app:layout_constraintEnd_toEndOf="parent"        app:layout_constraintStart_toStartOf="parent">        <Button            android:layout_width="@dimen/_24sdp"            android:layout_height="@dimen/_24sdp"            android:background="@drawable/ic_upload_download"            android:minHeight="0dp"            android:paddingTop="@dimen/_6sdp"            android:paddingBottom="@dimen/_6sdp"            android:textSize="@dimen/_13sdp"            app:layout_constraintBottom_toBottomOf="parent"            app:layout_constraintEnd_toEndOf="parent"            app:layout_constraintStart_toStartOf="parent"            app:layout_constraintTop_toTopOf="parent" />    </androidx.constraintlayout.widget.ConstraintLayout></androidx.constraintlayout.widget.ConstraintLayout>

So far so good. Let's have a look at the result

try this

    <?xml version="1.0" encoding="utf-8"?><android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:app="http://schemas.android.com/apk/res-auto"    xmlns:tools="http://schemas.android.com/tools"    android:id="@+id/container"    android:layout_width="match_parent"    android:layout_height="match_parent">    <ScrollView        android:layout_width="match_parent"        android:layout_height="match_parent"        android:layout_above="@+id/bottom_navigation"        android:layout_alignParentTop="true">        <LinearLayout            android:layout_width="match_parent"            android:layout_height="wrap_content"            android:orientation="vertical">            <android.support.v7.widget.CardView                android:layout_width="match_parent"                android:layout_height="50dp"                android:padding="15dp"                app:cardBackgroundColor="@color/red"                app:cardCornerRadius="4dp"                app:cardElevation="2dp">                <TextView                    android:layout_width="match_parent"                    android:layout_height="match_parent"                    android:gravity="center"                    android:text="Nilesh Rathod"                    android:textColor="#ffFFff" />            </android.support.v7.widget.CardView>            <android.support.v7.widget.CardView                android:layout_width="match_parent"                android:layout_height="50dp"                android:padding="15dp"                app:cardBackgroundColor="@color/colorPrimary"                app:cardCornerRadius="4dp"                app:cardElevation="2dp">                <TextView                    android:layout_width="match_parent"                    android:layout_height="match_parent"                    android:gravity="center"                    android:text="Nilesh Rathod"                    android:textColor="#ffFFff" />            </android.support.v7.widget.CardView>            <android.support.v7.widget.CardView                android:layout_width="match_parent"                android:layout_height="50dp"                android:padding="15dp"                app:cardBackgroundColor="@color/red"                app:cardCornerRadius="4dp"                app:cardElevation="2dp">                <TextView                    android:layout_width="match_parent"                    android:layout_height="match_parent"                    android:gravity="center"                    android:text="Nilesh Rathod"                    android:textColor="#ffFFff" />            </android.support.v7.widget.CardView>            <android.support.v7.widget.CardView                android:layout_width="match_parent"                android:layout_height="50dp"                android:padding="15dp"                app:cardBackgroundColor="@color/colorPrimary"                app:cardCornerRadius="4dp"                app:cardElevation="2dp">                <TextView                    android:layout_width="match_parent"                    android:layout_height="match_parent"                    android:gravity="center"                    android:text="Nilesh Rathod"                    android:textColor="#ffFFff" />            </android.support.v7.widget.CardView>            <android.support.v7.widget.CardView                android:layout_width="match_parent"                android:layout_height="50dp"                android:padding="15dp"                app:cardBackgroundColor="@color/red"                app:cardCornerRadius="4dp"                app:cardElevation="2dp">                <TextView                    android:layout_width="match_parent"                    android:layout_height="match_parent"                    android:gravity="center"                    android:text="Nilesh Rathod"                    android:textColor="#ffFFff" />            </android.support.v7.widget.CardView>            <android.support.v7.widget.CardView                android:layout_width="match_parent"                android:layout_height="50dp"                android:padding="15dp"                app:cardBackgroundColor="@color/colorPrimary"                app:cardCornerRadius="4dp"                app:cardElevation="2dp">                <TextView                    android:layout_width="match_parent"                    android:layout_height="match_parent"                    android:gravity="center"                    android:text="Nilesh Rathod"                    android:textColor="#ffFFff" />            </android.support.v7.widget.CardView>            <android.support.v7.widget.CardView                android:layout_width="match_parent"                android:layout_height="50dp"                android:padding="15dp"                app:cardBackgroundColor="@color/red"                app:cardCornerRadius="4dp"                app:cardElevation="2dp">                <TextView                    android:layout_width="match_parent"                    android:layout_height="match_parent"                    android:gravity="center"                    android:text="Nilesh Rathod"                    android:textColor="#ffFFff" />            </android.support.v7.widget.CardView>            <android.support.v7.widget.CardView                android:layout_width="match_parent"                android:layout_height="50dp"                android:padding="15dp"                app:cardBackgroundColor="@color/colorPrimary"                app:cardCornerRadius="4dp"                app:cardElevation="2dp">                <TextView                    android:layout_width="match_parent"                    android:layout_height="match_parent"                    android:gravity="center"                    android:text="Nilesh Rathod"                    android:textColor="#ffFFff" />            </android.support.v7.widget.CardView>            <android.support.v7.widget.CardView                android:layout_width="match_parent"                android:layout_height="50dp"                android:padding="15dp"                app:cardBackgroundColor="@color/red"                app:cardCornerRadius="4dp"                app:cardElevation="2dp">                <TextView                    android:layout_width="match_parent"                    android:layout_height="match_parent"                    android:gravity="center"                    android:text="Nilesh Rathod"                    android:textColor="#ffFFff" />            </android.support.v7.widget.CardView>            <android.support.v7.widget.CardView                android:layout_width="match_parent"                android:layout_height="50dp"                android:padding="15dp"                app:cardBackgroundColor="@color/colorPrimary"                app:cardCornerRadius="4dp"                app:cardElevation="2dp">                <TextView                    android:layout_width="match_parent"                    android:layout_height="match_parent"                    android:gravity="center"                    android:text="Nilesh Rathod"                    android:textColor="#ffFFff" />            </android.support.v7.widget.CardView>            <android.support.v7.widget.CardView                android:layout_width="match_parent"                android:layout_height="50dp"                android:padding="15dp"                app:cardBackgroundColor="@color/red"                app:cardCornerRadius="4dp"                app:cardElevation="2dp">                <TextView                    android:layout_width="match_parent"                    android:layout_height="match_parent"                    android:gravity="center"                    android:text="Nilesh Rathod"                    android:textColor="#ffFFff" />            </android.support.v7.widget.CardView>            <android.support.v7.widget.CardView                android:layout_width="match_parent"                android:layout_height="50dp"                android:padding="15dp"                app:cardBackgroundColor="@color/colorPrimary"                app:cardCornerRadius="4dp"                app:cardElevation="2dp">                <TextView                    android:layout_width="match_parent"                    android:layout_height="match_parent"                    android:gravity="center"                    android:text="Nilesh Rathod"                    android:textColor="#ffFFff" />            </android.support.v7.widget.CardView>        </LinearLayout>    </ScrollView>    <RelativeLayout        android:layout_width="match_parent"        android:layout_height="match_parent"        android:layout_gravity="bottom"        android:gravity="bottom">        <android.support.design.widget.BottomNavigationView            android:id="@+id/bottomnav"            android:layout_width="match_parent"            android:layout_height="56dp"            android:layout_weight="1"            android:background="@color/green"            android:foregroundGravity="bottom"            app:itemIconTint="@color/lightWhite"            app:itemTextColor="@color/lightWhite"            app:menu="@menu/menu"/>    </RelativeLayout></android.support.design.widget.CoordinatorLayout>

Result