Here's my take on solving that question. I removed your quick filter to allow the total sales value to be accessed and then calculated each store's reliance on footballs using a level of detail calculation. The y-axis is the same percent of total table calculation you had before, and the x-axis is the proportion of each store's football sales to each store's overall sales (references the LOD calculation).
The sample workbook is attached, as well as pictures below verifying that the percentages shown are correct.
Verification of percentages:
Graph showing percentages:
Best of luck!
Tableau Question2.twbx 28.7 KB
Excellent. I was able to recreate in my big workbook. Thanks so much for the help in learning some useful formulae.