Help for using set analysis in gauge chart

[#1]

Hi all, I am tryng to produce several gauge chart, wher each one has to show an average of values in a same field, selected  using other 2 fields (OP-CO and Area):

I would like to use a variable to select the value of the first field (OP-CO), but if  I use the variable name, the chart disappear (ex. 1), while if I put the exact value (ex. 2), it is correct:

Ex 1:      avg({$<[OP-CO] = {'$([OP-CO_1])'}, Area={'Quality'}>} [Assessment Value])

Ex 2:      avg({$<[OP-CO] = {'Denmark'}, Area={'Quality'}>} [Assessment Value])

Do I miss something?

Thanks a lot for helping!

Matteo

[#2]

SO number 2 works?

Im guessing that [OP_CO_1] is a field within OP-CO?

What do lock it as variable?

why not just do like in DENMARK?

[kaushiknsolanki]

Hi,

     Try this way.

     Create a variable vVariable1 = Denmark and then use the below expression.

     avg({$<[OP-CO] = {'$(vVariable1)'}, Area={'Quality'}>} [Assessment Value])

Regards,

Kaushik Solanki