Currently the course visibility for admins is based on which group or department the admins are managing. However, there are cases where an admin has user management rights for users but should not be able to manage a certain course for them.
Example: Admin manages some courses where he needs to be able to enroll and report on all users in the system. However there are also some courses (e.g. internal certification program, compliance courses) which contain sensible data and he should not be able to access the course and its reporting.