Combine filters - values and total in charts

[PrashantRupani]

Hi ,

I'm trying to get my head around this . 

I have a filter with a field titled Region from the table. That field has values like Region A, Region B .

The user would like to see one of the options in the drop down filter as Total besides Region A, Region B.

So there will be three values user will see in the filter - Total, Region A, Region B. When the user selects Region A, shows sales of Region A , show Region B when that is selected , but when they select Total show the total of Region A and B. 

I have written this below expression in the measure but do not know how to do I get it for total.  It gives me for Region A, B . Please advise. 

SUM({$<Region={"$(=GetFieldSelections(Region))"}>} measure)

[manoranjan_d]

Hi Prashant,

Please accept my suggestion as solution and close the thread, thanks for the support.

[PrashantRupani]

Thanks Gary for the detailed explanation. This helps a lot . I never knew until you told me about this. I learnt something new today. 

[PrashantRupani]

Thanks. I accepted it.