Previous months in set analysis

[Ribeiro]

I need to obtain in the set analysis below the months of

Oct 2021, Sep 2021, Aug 2021.

The month Nov 2021 is correct.

 aggr(FirstSortedValue([Previous],-Aggr(Min({<[CODIGOGRUPO]={'1'} >}Datex),Produto)),Produto)

It gave me a total blank.🤔

[Ribeiro]

aggr(FirstSortedValue([Previous],-
Aggr(Min({1<Ano ={$(=Year( addmonths( today() ,-1)))},Mes={$(=Month( addmonths( today() ,-1)))},[CODIGOGRUPO]={'1'} >}Datex),Produto)),Produto)

DID NOT WORK☹️

[Ribeiro · Accepted solution]

sum({<Ano ={$(=Year( addmonths( today() ,-4)))},Mes={$(=Month( addmonths( today() ,-4)))},DATAHORAX={'$(=MinString(DATAHORAX))'},[CODIGOGRUPO] = {'1'}>}Previous)

😀