Can you create a public submodule in a private directory?

I have a private GitHub repository that contains a TON of project files. I want to make a subset of these files available in a public repository. Is there a way to have a public submodule within a private directory?

If not, I will gladly take any suggestions on how a project like this might be organized.

Thanks in advance!

There’s no reason why it shouldn’t work. A submodule is just a reference on another repository, so you’d have to create a public repository containing the files you want to be public, and then add that as a submodule in your private repository. Note however that a submodule has to be in a directory, you cannot mix files from repository and submodule within one directory.