Grant side developers a partial access to a git repo

Question

Until now, I've been working on a project with a single and reliable agency.

However, I'd now like to speed up development by entrusting a few subjects to side developers. That means they need to access the repo, though I don't want them to get access to critical code.

Is there a way to grant them only a partial access to the repo (only the files I decided to show them), or to create (and maintain) a side repository, which doesn't includes some files/folders that I want to keep unknown to them ?

In other terms, I'd like these side developpers to work on the repo without granting them access to critical assets.

Answer 1

Despite my other answer I would actually recommend NOT using git submodules. They are confusing and not well understood. I've seen organizations use them and then yank them out afterwards.

I would personally consider using separate repos. I would add one task (shell script say) that combines (copies) the code into one place for use. I'd create an alias or function (allows parameters) to do this task