How to split a git repository while preserving subdirectories?

Question

What I want is similar to this question. However, I want the directory that is split into a separate repo to remain a subdirectory in that repo:

I have this:

Answer 1

If you wish split out just single directory as separate git repository

git-filter-branch has --subdirectory-filter option and it is much simpler then previous mentioned solutions, just:

git filter-branch --subdirectory-filter foodir -- --all

Additionally it change path and place content of directory on top of new repo, not just filter and remove other content.