Need to add a group/person in AME Approval chain

Hi,

Need help to achieve below requirement through AME in purchase requisition approval.

Per Person A, all Purchase Requisitions that are destined for his/her approval must first go to Person B.  This means that, even for people who don’t report into Person B, and for people who do report directly to Person A, Purchase Requisition Documents will not reach Person A directly, until Person B has approved them first.