Reporting numbers only for the first instance in a dataset

[Atanas_Atanasov]

Dear All,

Can anyone help me with a DAX calculation?
I have one and same opportunity for Sep 2023 and Nov 2023.
But I'd like to exclude the amount for Nov 2023 as it is a duplicate. but now sure how to check if the opportunity number is a duplicate in a first place...
The end result I am looking for is if I filter by Nov 2023 to see blanks for the country.
All due respect,
Atanas

[lukiz84]

can you show a diagram with the involved tables and relationships?

[Atanas_Atanasov]

Hello, 

Month & Year coming from the calendar table. New country name coming from the GEO Mapping table.

Opportunity ID coming from the OPP Snapshot Duplicate table.