I'm sorry, I still don't see it.  Maybe I need to share some more details.

My vendor sends several bills for each purchase order.  So, I will send PO1, and they will send me Bill1A, Bill1B, and Bill1C, at various times after the PO.  This is because they bill me when the product actually ships, and they might send multiple shipments.

I send POs for several different products (PO2 and PO3, let's say) so all of these bills will overlap each other in time.

Additionally, I might send a PO for a product before the previous PO is closed.  So I will receive a bill for the previous PO for that product after I send the following PO.

All this is to say that I am still just seeing a list of Purchase Orders and Bills sorted by date.  Neither the date nor amount of the transaction tells me anything about which purchase order a given bill is linked to, or not linked to.

What I had expected to be possible is to add a "Purchase Order" column to the report, so I could simply see the PO that a bill is linked to, and if it's blank, I would know it's not linked to a PO.  Is anything like that possible?

Please let me know if I am still misunderstanding the proposed solution.