How can i use a Variable with more variables on qliksense?

[#1]

Qliksense

im Try  Max(Month) its  Ok ,Works if i set on load script, but

if i try this:

SET vMonth=max(Month);  --> It Works.

SET vL.Test=pick(_Periods_ID,'Month={"=$(vMonth)"}','Month={"<=$(=max(Month))"}');  --> pick works, but just whit the first value.

i think is Dollar Sing "$"

Can  helpme, please.

Thanks