Use The fields that make up the group table to specify the fields you want to group. Click Get Fields to add all fields from the input stream(s) to the table.
The field names cannot contain spaces, dashes, or special characters, and must start with a
letter. The rows are sorted by the grouping fields. Right-click a row in the table to edit
that row or all rows in the table.
Note: You
can calculate aggregate functions over the whole dataset by leaving this table
blank.