Fork subdirectory of repo as a different repo in github

I don't think you can directly fork it on the web UI on github, but if you are ok cloning it and pushing things manually, you can do the following

• Clone the repo

  git clone https://github.com/theleagueof/chunk

• Create a branch using the git subtree command for the folder only

  git subtree split --prefix=folder_name -b new_branch

• Create a new github repo

• Add this new repo as a remote,

  git remote add upstream https://github.com/user/repo

• Push the subtree

  git push upstream new_branch

Github has posted an article how to do this at https://help.github.com/en/articles/splitting-a-subfolder-out-into-a-new-repository:

You can turn a folder within a Git repository into a brand new repository.

If you create a new clone of the repository, you won't lose any of your Git history or changes when you split a folder into a separate repository.

1. Open Terminal.

2. Change the current working directory to the location where you want to create your new repository.

3. Clone the repository that contains the subfolder.

   $ git clone https://github.com/USERNAME/REPOSITORY-NAME

4. Change the current working directory to your cloned repository.

   $ cd REPOSITORY-NAME

5. To filter out the subfolder from the rest of the files in the repository, run git filter-branch, supplying this information:

   • FOLDER-NAME: The folder within your project that you'd like to create a separate repository from.

   • BRANCH-NAME: The default branch for your current project, for example, master or gh-pages.

   $ git filter-branch --prune-empty --subdirectory-filter FOLDER-NAME  BRANCH-NAME  # Filter the specified branch in your directory and remove empty commits > Rewrite 48dc599c80e20527ed902928085e7861e6b3cbe6 (89/89) > Ref 'refs/heads/BRANCH-NAME' was rewritten 

   The repository should now only contain the files that were in your subfolder.

6. Create a new repository on GitHub.

7. At the top of your new GitHub repository's Quick Setup page, click the clipboard to copy the remote repository URL.

   • Copy remote repository URL field

8. Check the existing remote name for your repository. For example, origin or upstream are two common choices.

   $ git remote -v > origin  https://github.com/USERNAME/REPOSITORY-NAME.git (fetch)  > origin  https://github.com/USERNAME/REPOSITORY-NAME.git (push)

9. Set up a new remote URL for your new repository using the existing remote name and the remote repository URL you copied in step 7.

   git remote set-url originhttps://github.com/USERNAME/NEW-REPOSITORY-NAME.git

10. Verify that the remote URL has changed with your new repository name.

    $ git remote -v # Verify new remote URL > origin  https://github.com/USERNAME/NEW-REPOSITORY-NAME.git (fetch) > origin  https://github.com/USERNAME/NEW-REPOSITORY-NAME.git (push)

11. Push your changes to the new repository on GitHub.

    git push -u origin BRANCH-NAME