How to pass a set analysis function as value to another set analysis?

[#1]

Please help me to solve the below issue.

First Set analysis function.

Sum({<[Budget_Year='{2013'},Budget_Quarter={'Q2'}]>}Budget)

I want to pass this set analysis function to another set analysis function as value.

like

Sum({<[Financial_Year={'2013'},Budget_Quarter={'Q2'}]>}Sum({<[Budget_Year='{2013'},Budget_Quarter={'Q2'}]>}Budget)) +

Is this Possible to give the another set analysis  function as value in Set analysis.

or is it  possible to give variable as value in set analysis as below?

Sum({<[Budget_Year='{2013'},Budget_Quarter={'Q2'}]>}($vBudget)).

Please let me know how to solve this issue.

[Gysbert_Wassenaar]

If you want to nest aggregations, i.e. calculated the sum of another sum, then you need to use the aggr function and specify over which dimensions the inner sum should be aggregated. I don't understand what you're actually trying to do. Can you prepare an example document with some data and the results you expect?