Need ability to add the BPA number to a new line item added via Edit Order on the Requisition screen

Summary:

We have been able to use page composer and add the + sign to the lines under the Edit Order Requisition screen. Need to know how to add the source document number to the new line item. If I search for a Contract Purchase Agreement the number will come up but for a Blanket Purchase Agreement (BPA) it doesn't pull up the number and says no results found. Any suggestions on how I can have any source document type to show up and ability to select BPA and line item on the edit line screen. If the