Filtering a Lookup Values based on another field loolup value

HI Experts,

Two Questions:

#1. I am trying to filter a lookup field value  based on another field value (Lookup based) on a PDP in Project Server.

#2. Can we define Security in project server for only a particular PDP Page, so that only the group assigned to that PDP page can only modify the fields in the PDP. (Apart from breaking the inherited permissions).

Thanks.