However, the proposed solution is almost correct, but the 16PRO doesn't show up in the legend.
For additional info, I'm trying to create a combo chart that represents the selected SKU_CODE(16PRO) vs the COMPETITOR_SKU_CODE (16FS). That is why in my set analysis I used "+" to compare the selected SKU_CODE and also its competitor. Because the SKU_CODE column and COMPETITOR_SKU_CODE column are from 2 different table. And if I joined both of the column, the result would be duplicated, since the relationship between those 2 tables is 1 to Many.