Group By Operation:

Group rows by selected columns, applying the specified aggregation functions to relative selected member columns

The operation result expected is similar to:

SELECT K,K',...,f(X),f'(X'),...,CONST,CONST'...
FROM [TARGET_TABLE]
GROUP BY K,K',...

where:
K,K'... are the columns to group by
f(X),f'(X')... are the aggregation functions to apply to selected columns
CONST,CONST'... are constant default values for remaining columns