Model Design

Issue:
I want to calculate the % of a set of Values based on the fields a user may or maynot added to a Table/Chart

For example

If I have three fields , in reality I have 60 plus dimension columns

1. Product Category
2. Product
3. Sales Amount

I can create

• A measure to Calculcate the % of Sales for each product
• A second measure to Calculcate the % of Sales for each product By Category

Question

Is it possible to create a measure to illustrate % , regardles of the combinations of dimensions , it will illustrate correctlty

( I assume it is called a dynamic Measure)

If a user adds product and / OR Category , location ; it will calculate the % in realtime

Do I need to create measures for every combination and use a switch statement to toggle between them ? If you have 100 plus diemnsions columns, not sure how feasible this is
What is the best practice to accomodate this?