Restricting Learning Specialist role to specific department

Hi Everyone,

We have specific department Learning Specialist custom role when we assign that role to any employee he/she should be able to access only the employees who are belongs to that department (Ex: Govt School Department) but not other department employees.

We have created custom data role and assign it to an employee. When we login as that employee and navigate to

My Clint Groups> Learning> Catalog Management> Offerings > Try to assign one offering to learner

As per the role design the employee should be able to access only the employees who are belongs Govt School department. But it's showing other department employees person number and names as well;