Operations on dimension members

Hi Experts!!

I need ideas to solve this requirement that is a bit strange;

Initially I have a KPI and a dimension, which it crosses by.

When I drill down on the TOTAL PROCESO, I can check the values for the members of the dimension;

What I need; assign weight for each member (example: Gobierno Corporativo 60%, Planeación Estratégica 40%)

And calculate a formula for the TARDEV like this;

(A * 60%) +  (B * 40%)

any idea how to do this??

thanks a lot!!