Could you provide some mocked up data in a TWBX (packaged Tableau workbook) along with the results you'd expect to see? Either that, or can you elaborate on what you are doing with these three averages once you have them calculated to determine that the combo is one of the top values?
One or both of these should help I or somebody else get you moving in the right direction.
As per my understanding try this, it might be helped U,
create two Calculated Fields Test, SrNo.
1) Test-> AVG(money spent)+AVG(credit limit) +AVG(another measure)
2) SrNo-> index()
3) convert SrNo to Discrete
4) Use on SrNo->Edit table Calculation-> Specific dimension->Custom Sort->Descending based on Test
and sort Customer's in descending order based on Test.
might be some easy option available. i have tried this