Replace a value from calculated value to a mun

[manu2105]

total([H0 Sales] within set  periodstoDate([Agency Sales - Daily].[Business Days].[All Business Days].[All
Business Days],[Agency Sales - Daily].[Business Days].[All Business Days].[Business Days]->:[PC].[@MEMBER].[21]))

Hi for the above Mun works and I want to replace the value 21 with a query item

tuple([Current Month], BusinessDays) -   this tuple is created as calculated measure and it will return 21 or 22 based on the current month ,

I dont know how to put this query output to 21

Thanks,