I had an issue where approvals were routed to a different supervisor like 5 PO's then later changed the supervisor to the correct one. How do i approve those previous PO's that were sent to the wrong supervisor who is currently not working with us

depends how your approvals are set up - if you're using advanced approvals that's what the super approver is useful for. you can also try cancelling the existing workflow and having them re-submit for approval, but that may or may not cause issues depending on your approval flow