What's the meaning of this expression?

[#1]

Hi everybody

I'd like to know what's doing the "={$1} " in the set analysis

SUM({<Year={"$(=max(Year))"}, Month=, , MonthName={$1}>} Money)

Thanks,

Regards

[sunny_talwar]

I have no idea, never seen this before.... Seen this used here once in a while (https://help.qlik.com/en-US/qlikview/12.0/Subsystems/Client/Content/ChartFunctions/SetAnalysis/set-a...)

Sum({$1<Year={"$(=max(Year))"}, Month=, , MonthName={$1}>} Money)

But never seen it used against a field

[maxgro]

maybe a parameter

look at the attachment