You can perform this by using set expressions.
Let me explain, Sum(income) is the expression we're working with. Now, if I want to just focus on some income, like in your case, juste sum(income) of the cats.
This is how we should proceed, go to same expression and edit it as follow:
1) the first step is to add {<>} : sum({<>}income) : this is where we're going to add our 'condition'
2) enter the condition : [Managed Section 05] = {‘Cats’}
a) Let's explain this: [Managed Section 05] is the field we're working with. We want to make selections in the field. In fact we want only to work with "Cats" => [Managed Section 05]= { 'Cats' } (we allways open the {} to put a value in, if the value is numeric, don't use quotes , if it's a string like in our case, use the quotes; if it's an expression, please surround it with double quotes..)
3) Now, the expression has become like this : sum({< [Managed Section 05] = {‘Cats’} >} income) : and this is how we read it : The sum of income for the managed section05 which has a value = Cats.
Hope this answered your question !
Omar,
