Good Technical knowledge question: you may not achieve this in Tableau but you have option to write custom SQL to pull the customers and the products which they never purchased.
select customerid,productname,sum(sales) from Table A group by customer id,product name........ with this you have the customers and products they purchased...
now the main query select b.customerid,a.product id from customer B where b.customerid=a.customerid.... need to rethink same in multiple methods to get it... mostly your oracle dba will hep you in writing stored procedure to get this information... hope this information helps you to rethink and debug in different way...
This thread will not exactly match your desired result, but could provide some insight into possible strategies.
The answer will allow you to see Customers that purchased "Item A" but did not purchase "Item B" (Items selected with Parameters).
Hope this helps,