Custom breadcrumbs with list of children (categories or pages)

Here's the basic function that hopefully should get you or someone else in the right direction:

function so_63339155_get_page_hierarchy($post = null): array{    // Make sure we have something    $post = get_post($post);    if (!$post) {        return [];    }    // This will get all Post IDs of the "parent" objects    $ancestors = get_post_ancestors($post);    if (0 === count($ancestors)) {        return [];    }    $ret = [];    foreach ($ancestors as $postId) {        // Grab the children for the page.        // NOTE: This can take additional arguments such as sort order and visibility        $ret[$postId] = get_children($postId);    }    return $ret;}

Querying the site's hierarchy and getting object data for a lot of posts can be a little expensive, so you might want to check into some caching.

The above code uses the native hierarchy system for pages and should work for any CPT that is based off of the page type. It does not support taxonomy terms, that is a similar but different beast. It also does not take the home/front page on the beginning or the current page on the end, but that can be adapted pretty easily, too.

The result is an array whose keys are Post IDs for the parents and whose values are WP_Post objects of the children, so get_post() will need to be called one more time on the keys, and you'll want to call get_permalink() to get the URLs.

Try this code it's working from my side.

function custom_breadcrumbs(){    // Set variables for later use    $here_text        = __( 'You are currently here!' );    $home_link        = home_url('/');    $home_text        = __( 'Home' );    $link_before      = '<span typeof="v:Breadcrumb">';    $link_after       = '</span>';    $link_attr        = ' rel="v:url" property="v:title"';    $link             = $link_before . '<a' . $link_attr . ' href="%1$s">%2$s</a>' . $link_after;    $delimiter        = ' » ';              // Delimiter between crumbs    $before           = '<span class="current">'; // Tag before the current crumb    $after            = '</span>';                // Tag after the current crumb    $page_addon       = '';                       // Adds the page number if the query is paged    $breadcrumb_trail = '';    $category_links   = '';    /**      * Set our own $wp_the_query variable. Do not use the global variable version due to      * reliability     */    $wp_the_query   = $GLOBALS['wp_the_query'];    $queried_object = $wp_the_query->get_queried_object();    // Handle single post requests which includes single pages, posts and attatchments    if ( is_singular() )     {        /**          * Set our own $post variable. Do not use the global variable version due to          * reliability. We will set $post_object variable to $GLOBALS['wp_the_query']         */        $post_object = sanitize_post( $queried_object );        // Set variables         $title          = apply_filters( 'the_title', $post_object->post_title );        $parent         = $post_object->post_parent;        $post_type      = $post_object->post_type;        $post_id        = $post_object->ID;        $post_link      = $before . $title . $after;        $parent_string  = '';        $post_type_link = '';        if ( 'post' === $post_type )         {            // Get the post categories            $categories = get_the_category( $post_id );            if ( $categories ) {                // Lets grab the first category                $category  = $categories[0];                $category_links = get_category_parents( $category, true, $delimiter );                $category_links = str_replace( '<a',   $link_before . '<a' . $link_attr, $category_links );                $category_links = str_replace( '</a>', '</a>' . $link_after,             $category_links );            }        }        if ( !in_array( $post_type, ['post', 'page', 'attachment'] ) )        {            $post_type_object = get_post_type_object( $post_type );            $archive_link     = esc_url( get_post_type_archive_link( $post_type ) );            $post_type_link   = sprintf( $link, $archive_link, $post_type_object->labels->singular_name );        }        // Get post parents if $parent !== 0        if ( 0 !== $parent )         {            $parent_links = [];            while ( $parent ) {                $post_parent = get_post( $parent );                $parent_links[] = sprintf( $link, esc_url( get_permalink( $post_parent->ID ) ), get_the_title( $post_parent->ID ) );                $parent = $post_parent->post_parent;            }            $parent_links = array_reverse( $parent_links );            $parent_string = implode( $delimiter, $parent_links );        }        // Lets build the breadcrumb trail        if ( $parent_string ) {            $breadcrumb_trail = $parent_string . $delimiter . $post_link;        } else {            $breadcrumb_trail = $post_link;        }        if ( $post_type_link )            $breadcrumb_trail = $post_type_link . $delimiter . $breadcrumb_trail;        if ( $category_links )            $breadcrumb_trail = $category_links . $breadcrumb_trail;    }    // Handle archives which includes category-, tag-, taxonomy-, date-, custom post type archives and author archives    if( is_archive() )    {        if (    is_category()             || is_tag()             || is_tax()        ) {            // Set the variables for this section            $term_object        = get_term( $queried_object );            $taxonomy           = $term_object->taxonomy;            $term_id            = $term_object->term_id;            $term_name          = $term_object->name;            $term_parent        = $term_object->parent;            $taxonomy_object    = get_taxonomy( $taxonomy );            $current_term_link  = $before . $taxonomy_object->labels->singular_name . ': ' . $term_name . $after;            $parent_term_string = '';            if ( 0 !== $term_parent )            {                // Get all the current term ancestors                $parent_term_links = [];                while ( $term_parent ) {                    $term = get_term( $term_parent, $taxonomy );                    $parent_term_links[] = sprintf( $link, esc_url( get_term_link( $term ) ), $term->name );                    $term_parent = $term->parent;                }                $parent_term_links  = array_reverse( $parent_term_links );                $parent_term_string = implode( $delimiter, $parent_term_links );            }            if ( $parent_term_string ) {                $breadcrumb_trail = $parent_term_string . $delimiter . $current_term_link;            } else {                $breadcrumb_trail = $current_term_link;            }        } elseif ( is_author() ) {            $breadcrumb_trail = __( 'Author archive for ') .  $before . $queried_object->data->display_name . $after;        } elseif ( is_date() ) {            // Set default variables            $year     = $wp_the_query->query_vars['year'];            $monthnum = $wp_the_query->query_vars['monthnum'];            $day      = $wp_the_query->query_vars['day'];            // Get the month name if $monthnum has a value            if ( $monthnum ) {                $date_time  = DateTime::createFromFormat( '!m', $monthnum );                $month_name = $date_time->format( 'F' );            }            if ( is_year() ) {                $breadcrumb_trail = $before . $year . $after;            } elseif( is_month() ) {                $year_link        = sprintf( $link, esc_url( get_year_link( $year ) ), $year );                $breadcrumb_trail = $year_link . $delimiter . $before . $month_name . $after;            } elseif( is_day() ) {                $year_link        = sprintf( $link, esc_url( get_year_link( $year ) ),             $year       );                $month_link       = sprintf( $link, esc_url( get_month_link( $year, $monthnum ) ), $month_name );                $breadcrumb_trail = $year_link . $delimiter . $month_link . $delimiter . $before . $day . $after;            }        } elseif ( is_post_type_archive() ) {            $post_type        = $wp_the_query->query_vars['post_type'];            $post_type_object = get_post_type_object( $post_type );            $breadcrumb_trail = $before . $post_type_object->labels->singular_name . $after;        }    }       // Handle the search page    if ( is_search() ) {        $breadcrumb_trail = __( 'Search query for: ' ) . $before . get_search_query() . $after;    }    // Handle 404's    if ( is_404() ) {        $breadcrumb_trail = $before . __( 'Error 404' ) . $after;    }    // Handle paged pages    if ( is_paged() ) {        $current_page = get_query_var( 'paged' ) ? get_query_var( 'paged' ) : get_query_var( 'page' );        $page_addon   = $before . sprintf( __( ' ( Page %s )' ), number_format_i18n( $current_page ) ) . $after;    }    $breadcrumb_output_link  = '';    $breadcrumb_output_link .= '<div class="breadcrumb">';    if (    is_home()         || is_front_page()    ) {        // Do not show breadcrumbs on page one of home and frontpage        if ( is_paged() ) {            $breadcrumb_output_link .= $here_text . $delimiter;            $breadcrumb_output_link .= '<a href="' . $home_link . '">' . $home_text . '</a>';            $breadcrumb_output_link .= $page_addon;        }    } else {        $breadcrumb_output_link .= $here_text . $delimiter;        $breadcrumb_output_link .= '<a href="' . $home_link . '" rel="v:url" property="v:title">' . $home_text . '</a>';        $breadcrumb_output_link .= $delimiter;        $breadcrumb_output_link .= $breadcrumb_trail;        $breadcrumb_output_link .= $page_addon;    }    $breadcrumb_output_link .= '</div><!-- .breadcrumbs -->';    return $breadcrumb_output_link;}add_shortcode('custom_breadcrumbs','custom_breadcrumbs');

Display breadcrumbs code

echo do_shortcode('[custom_breadcrumbs]');