AP Invoice approval parallel routing to Inv Distrib DFF user and Requster approver at the same time

Summary:

The Business requirement is to trigger both the DFF and the invoice header level requester field to be routed parallel for approval at the same time. Basically it will send approval to the person in the DFF and the person as the requester.

We tried to send the approvals in parallel (distribution DFF approver & invoice header requestor) at the same time. But it's getting error.

Ex: If person "A" is creating invoice and person "B" is assigned in invoice header requestor field, and also Person "C" is assigned as a Distribution >>DFF attribute 1 (Line level)>>>Approver. Then the approval should parallely go to Person "B" & "C" at the same time. Please let us if its feasible to execute through invoice approval workflow.