Having 2 Modules Directory

Hello

I will need to create 2 directories modules for my app. People will have the possibility to create/add modules with this external directory

So my question will be can we create 2 repository modules ?

The first one it s for the app and the second for the people to add.

My first ideas was to create a symbolique link but not perfect in my way

Second will be to create sub module but also not super clean.