Restrict Internal Extension Calls Outgoing

Most of the businesses have Departments and each department have HOD and the Structure is formed as a Tree. 

Sensitive cases like Businesses where there are Multiple Directors and some directors need to restrict the Junior Staff Extensions to call His Extension.

Example: 
Business Director or owner do not want to get calls from Extension 500 (Retail Outlet) in the ground floor,

This is a Simple requirement to Restrict calls in between extensions locally from group to group or individual extensions.