set analysis - disregard all selections except one

[#1]

How do i do this?

So, Sum ({1} Amount) would give me sum of all disregarding all selections. What i want is sum of all for 'business lead = current business lead selection' and disregarding all other selections.

[goldnejea8]

sum({<Field1=,Field2=,Field3=,..........,[Business Lead]={[Current Business Lead Selection]}>}Amount)