Here is some more documentation I found on how to show NOT the top products overall, but the top products month by month: How to Find the Top Performers Over Time with Table Calculations

I just had this problem earlier today. Another workaround if you aren’t diving into the coding world is to Merge Results. I merged a table within looker that only showed the top 5 products (sorting sales and using row limits), to a table with daily p...

Look here to solve the problem by creating a Yes/No custom table calculation. Worked like a charm for me!