Help with a measure

Hi All,

Need help in solving below query in Powerbi/Power Pivot.

In Powerpivot I created a Pivottable similar to below, where I created a measure COGP which is sum of RM, PM & Production cost. Now what I need to do is calculate % of COGP for each category and allocate Supply Chain OH accordingly. I have given the Supply Chain OH value at total level. One option I found is to calculate total of each this column (RM, PM, Prod) using All function with calculate and then calculate the contribution. Which is not a good option for me as my model contains more than 10 of this columns. 

Is it possible to calculate the % contribution of a measure itself which I can use to multiply a certain value?