I think it is extremely important that a function is made available in the software that is extremely important for small and large companies. companies with administrators have secretaries and administrators should not receive direct internal calls. it would be important to have an option to define which extensions can call a number directly and that all the others be forwarded to the secretary.
1001 vice president.
1000 only receives calls from 1001 and 1010, all other extensions, calls to 1000 must be forwarded to 1010.