The "SalesTxn Document Actual Discount Amount" is what was actually discounted on the invoice. Remember that it is a document field, so it is repeated for each line on the invoice. Use PowerPivot to grab the unique value for each invoice.
To get the discount on an invoice by invoice basis use the patented feature in the QQube General Ledger Detail subject where linked transactions are grouped in consecutive rows. The master link # is actually the QB Transaction number.
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