How to write a set analysis equation for select the sum of sales for the most recent selected month, or the most recent month if none has been selected

[#1]

How to write a set analysis equation for select the sum of sales for the most recent selected month, or the most recent month if none has been selected

[bbi_mba_76]

Hi,

I don't understand so much, maybe with

=Sum({<Month = {"=$(=Max(Month))"}>} Value)