Equations with Direct Query. Creating a percentage from total

Hello Power BI Community, I'm still pretty new to using Power BI. And for the first time I'm using direct query instead of an import. This is giving me some issues. What I want to do is divide the pounds of materials of our top 10 materials by our yearly amount of material. I want to get a percentage of how much of our top 10 materials we use in comparision to the total amount in a year. I would know how to do this if this was an import and create a new a column measure. But I can't seem to do this direct query. Does anyone have some insight? Any help would be appreciated!