In advanced mode, you can use hierarchical fields that represent an array, map, or struct.
You can use hierarchical fields as pass-through fields. You can also use complex operators to access a primitive child field and use the child field to perform an aggregate calculation. For example, you can use the dot operator to access an integer in a struct field and pass the integer as an argument to the SUM function. For more information about complex operators, see Function Reference.
Consider the following guidelines when you use hierarchical fields:
•You cannot use a hierarchical field as a group by field.
•The output of an aggregate calculation cannot be an array, map, or struct.