Prohibit Manager from approving Requisition once it goes from his queue to next queue.
Person A -Requestor
Person B - Level 1 Approver(Manager)
Person C- Level 2 Approver(comes under Manager B)
The requestor has submitted one Req for approval and it will go to the first approver(Person A) after his approval it will go to the Second level(person C) approver for approval.
Now let's assume that Person B has approved the PR from his queue and the PR will get assigned to Person C.
As explained the B is the manager of A and C, so he can see the PR is pending approval with C in BPM.
How to restrict B from approving the PR which should technically be approved by C.