Two Operating units for one approver at Post List Approver Group (AP Invoice Approval AME)

Hi

We are in R12.3. We have implemented AME for AP invoice Approval.

Currently the approval initiate through supervisor level (Chain of Authority)  then parallel approval is been setup under chain of authority where first responder wins. The third level approval is setup as Post List Approval Group.

Supervisor level Approval (Chain of Authority) --> Parallel Approval (chain of authority) --> Post list Approval Group - Invoice gets Approved

We are encountering an issue when a new operating unit is defined and required a similar approval process. Under the new operating unit when the parallel approval is received, invoice gets approved.