How to assign approvals to ISP PO matched invoice before and after validation

Summary:

When the supplier submits the PO-matched invoice via the supplier portal, it will first go for approval to the first group. After an invoice is approved, the user adds details in header DFFs and validates the invoice. After validation user wants to submit the invoice for reapproval to another group but the system doesn't allow him as an invoice is already workflow approved.

Currently, we can only assign approval either before validation or after validation.

Is there any way to achieve this double approval?

Content (please ensure you mask any confidential information):

Version (include the version you are using, if applicable):