Unable to set approval rule for BPA document via DFF

Summary:

As per "Doc ID 2434088.1)" we have followed all the step as per document but not getting attribute (DFF value) value to assign as a resource.

We need to use the highlighted attribute user into BPA document approval, where based on selected employee approval should flow and approval should flow based on position hierarchy.

I am trying to use following payload

HierarchyBuilder.getManager("position",PurchasingDocumentHeader.aggregateAttr3,-1,"","Position Hierarchy Tree")

But getting following error. please support me on using correct the payload