Restricting users in a particular responsibility

Hi,

I have created one new AP responsibility with 2 operating units assigned to it. It is a readonly responsibility to inquire the past transactions and invoices. Now I want that the users of a particular region should be able to view the transactions of their region only.

For example:

resp name: XYZ

Menu: invoices

           payments

           suppliers

           purchasing

           others

OU assigned: Ame (America region)

                       Aus (Australia)

Now I want that when the America user opens the 'invoices' menu then it should be able to view only the 'Ame' invoices and not the 'Aus' ones.

Is there any way to achieve this?