How can I add a specific folder from a git repo as a git submodule?

Question

I have a git repo and I want to add a submodule to it. Problem is, the submodule exists as a folder inside another repo. Can I add only that folder as a submodule?

Answer 1

1. Create new branch
2. Move required files to new branch
3. Add sub module to super repository
4. Checkout sub-module to new branch