Discount total in sales order

Summary

Requirement to trigger approval based on total discount amount

Content

I am trying to trigger sales order approval based on total discount amount of order.

I came across an attribute ORDER_TOTAL_TYPE in approval. the Lov contains, List price, Net Price, Paynow, Discount etc. When tried defining Order total type as Discount and make use of order total amount which now would be discount total amount, i couldnt see expected results.

Has anyone made use of this field earlier ?

Version

21A