Can we filter the “Customer” list by product so we know which product the customers have bought?

Yes, you can achieve this by following these steps:

1. Go to the “Contacts” tab > Navigate to “list” > Open “Customers” List.

2.Go to “Apply Filter” >  contact properties > products bought > Select “contains any of” > Enter name(slug) of your product, you will see the contacts who bought those products.