The concept of P() and E() can also be used with two fields for comparison inside the nested sets.

For example: if you need to find out all those customers where the suppliers had a volume of 300, the set expression in the Sales measure will be defined in the following way:

Sum({$<Customer=p({1<Volume={300}>}Supplier)>}Sales) 

Here, the P() element function returns a list of possible suppliers who had a volume of 300. The list of suppliers is then matched to the customers to make the relevant selections.

The resultant table will look similar to the following:

An E() function in place of P() will result in all the customers whose suppliers never had a volume of 300: