Error in Set modifier expression

[Iwin]

Hi,

I want to calculate a measure based on the range of values of another measure.

i have used below expression :

sum({<((sum([1_Forecast Quantity ZU Unit])-sum([Sales Qty ZU CHK]))*100)/sum([Sales Qty ZU CHK])={">=-15<=20"}>}
aggr($(vSalesValueDerived),[Country key TEXT],Material,[Forecast Accuracy Period],[Profit Center]$(vRadio_Button))))

Here I want to calculate value of Sales value derived based on the range of measure :

(sum([1_Forecast Quantity ZU Unit])-sum([Sales Qty ZU CHK]))*100)/sum([Sales Qty ZU CHK]) where its value is greater than -15 and less than 20

However it is giving error in set modifiers because of measure used as a field.

What can be an alternate way to calculate this and is it possible using set analysis?

Also I have to sum the modifier else value doesnt come.

Thanks.