Restrict Grades section under Workforce Structure

Dears,

We have a requirement to restrict Grades section under Workforce Structure, so only certain HR admins will be able to see/add/change grade related data. I tried to find the privilege which gives access to Grades, but didn't. I think there is not an exact privilege which gives access to Grades, I think there is a common privilege for Workforce Structure and if user has this privilege, then he is able to see all sections under Workforce Structure. Also tried Page Composer, but failed: I tried to show Grades section only to users who has a certain custom role using EL