I have three lists: Product Lines L1, Product Category L2, Products L3. Total Products is the top level of Product Lines L1. I'm trying to calculate the product mix of each product in Products L3 as a percentage of Total Products. The module.line item that has the volume is Sales.Units Sold. But my question isn't about the mix calculation. I'm first concerned with just trying to get the Total Products value from the Sales module. I've tried a number of different formulas, but nothing seems to work. So how do I get the Units Sold value at the top level?