Transfers a Git file from one repository to another while maintaining its Git history.

transfer.sh

git filter-branch --prune-empty --subdirectory-filter <DIRECTORY TO FILTER> -- --all
git filter-branch -f --prune-empty --index-filter 'git rm --cached --ignore-unmatch $(git ls-files | grep -v "<FILE TO FILTER>")'
git reset --hard
git remote rm origin
git gc --aggressive
git prune