PO Approval Status

We have a PO that was topped up by $600,000. The approval was forwarded to Employee A who approved it, and then it flowed to Employee B who also approved it. We suspect the approval continued on because of the approval limits: Employee A ($500,000) and Employee B ($1,000,000).

Is there a way (field in a table) to determine if a PO has been partially approved (Employee A) verse finally approved (Employee B)? In other words, the PO has been approved and does not require further approvals.