Grant permissions on the specific folder in repository

Hi Everyone,

I want to implement a following use case:

  1. We have a repository ‘R’ containing the folders and some files (Folder-1,Folder-2,Folder-3, File-1, File-2)
  2. User creates his feature branch (A) from dev branch.
  3. When user will create the merge request for Dev branch, only the changes done in Folder-1 and File-1 can only be the part of this merge request. Because User don’t have permission to include changes in Folder-2, Folder-3 and File-2 in merge request to Dev. But user can commit everything in his feature branch.

How can I make this happen? How I can implement this use case in gitlab?

Thanks in advance.