Sales report showing for a select group of Items how many each customer bought monthly?

A client who wholesales seafood needed to see monthly sales for two specific items by customer.

One product is an alternative product option to the other so they want to see how often and how much each client buys the newer product.

1. Run Sales Monthly - Pivot report - this shows monthly $Sales by customer for the past 12 months
2. Filter to select the Items or Item Group/Brand to compare
3. Analyse by Item or Item Group to change the rows from Customer to Item or Item Group
4. Group by Customer 
5. Display - choose to display Qty, $ Total Sales or a combination of these using the Pivot Display options

See below how the final report looks when displaying just Qty sold.