Restrict "Parent Item" when creating content

Hello,
I would like to know how to restrict where authors are allowed to post their content, for instance say I Have Link A and Link B in Primary Links and want users with role Author A to select only Primary Links-Link A and below when posting their pages and Author B to choose only Primary Links-Link B and below, how do i do this ?

What's more is it possible to choose which part of a menu a user is able to edit ?

Thank you