Restriction required for Project Organizations access

Dear Team,

Greetings..

Kindly help me for the following for Oracle Project Costing Module:

Organization has one OU. Two different Project Organizations assigned to the OU in the project hierarchy.

Can we restrict access to One Organization for one user. i.e.

For Example

     1) Organization A

     2) Organization B

Can we restrict (Oracle Projects) the access Organization A users to Organization B.

I tried with Organization Authority Functionality. But not getting expected result.

Please reply in this. And is there any option to achieve the requirement.

Regards,

Narasimha Rao.