1
Returns the Sum of Sales for the current selection, but only for those customers that have bought the product "Shoe".
(This is one of the examples of the "QlikView Help").
Sum({$<Customer=P({1<Product={'Shoe'}>}Customer)>}Sales)
2
Return the Sum of Sales for the current selection, but only for those customers who have ever supplied the product "Shoe".
Sum({$<Customer=P({1<Product={'Shoe'}>}Supplier)>}Sales)