Need to set the approval on the PO line level against the PR line

Summary:

We have a requirement where we need to derive the PO approvals from the PR-PO-backed lines available on the PO. The condition is as follows:

if the PO line amount is higher than the PR line then it needs to trigger the PR-based Supervisory approval hierarchy. And if the amount is the same or less then it needs to trigger the Buyer approval hierarchy.

Now, the buyer based hierarchy is straightforward which is created and working well, the issue we are facing is when we increase the PO line amount the system does not trigger the Requester Supervisory hierarchy. Apart from this, if the purchase order is a mixture of multiple requisitions then the system does not deliver the approval to the individual supervisor.