More than 2 Key figure in calculation

Hi All,

Can we give more than 2 key figures as inputs in key figure calculation. There is an example of case statement mentioned in configuration guide. I am trying to do something similar but it gives me error of more than 2 key figures in calculation.

CASE(SELECTEDOPTION@PERPROD, 1, KF1@PERPROD, 2, KF2@PERRPROD,KF@PERPROD)