Hi Guys!

I am working in Power BI Desktop (Similar as Power Query) which uses DAX. I have 3 columns:, Response ID, Brand and Volume. Since I have around 50 brands per ID, the Response ID is shown 50 times. Now I want to summarize the total volume PER Response ID in a separate column, but when I use a SUM function, it sums all response ID's up while I want to sum the volume based on response ID (Thus combining the volume of the 50 brands into one sum showing for each ID, thus 50 times the same value per ID). Simply grouping wouldn't work since I later want to calculate the marketshare per ID.


Now I am new in DAX so I haven't found the right formula yet.

Anyone any idea how to pull this one off?