QlikView Expression that ignores some selections and contains where explicit values

Question

I have a basic expression SUM(value).

I want to modify this expression so it does 2 things:

Ignores all list box selections except one (yearperiod) and contains explicit where conditions.

Pseudo expected expression:

(SUM(value) Where category = 'abc'/SUM(TOTAL value Where category = 'abc' OR 'xyz' (NOT AFFECTED BY yearperiod))

Answer 1

This can be achieved by using set analysis.

SUM({1<yearperiod  = $:: yearperiod, Category = {'abc'} >}Value)/SUM(TOTAL {1<yearperiod  = $:: yearperiod, Category = {'abc','xyz'} >}Value)