How to use SUM and LOOKUP dynamically
I have Order module(Region, Order)
Order(1,2...) comes from each Region. Order has Item and Amount.
I want to aggregate item-amount by dynamic Region like this table.
If Users chose the Europe, Item-Amount Table is aggregated by Europe.
I tried SUM and LOOKUP but I couldn't.
The point is I don't need Region List in Item-Amount table because it consumes memories.
And I don't want to use List Subset function because dynamic region setting has another dimension.
( I omitted the instructions to explain briefly)