How to maintain related projects on github?

Question

git

There is a main product and additional modules (to fill the database). The entire team should have access to the product, and only the team leader should have access to the modules. One issue can affect the change of both modules and the project, respectively, they must be in the same branch.
How can they be distinguished?
Now we have 2 repositories, but this is inconvenient (due to the requirements for the issue and branches).
It was not possible to make an investment either (maybe I'm a krivoruk). Doesn't want to commit something in the nested repository.
project (teamlid repository)
-core (repository for everyone. Its teamlid repository does not load, but should)
-moduls

Answer 1

Write an issue in the main part of the project.
You can comment (but this is not necessary if the developers themselves have a mustache) what other turnips this change affects.
GitHub itself can create links.
Or, consider using GitLab rather than GitHub. It's more suited to related raps.

Answer 2

No way. Separate changes. The module from the application must be separated by an abstraction. And changing the abstraction does not affect the modules. So and vice versa.
If the modules are strongly related, then you need to throw them into core.