Once the sorting of a particular field has been determined, a control level is created. At the end of this control level, subtotals appear for all numeric fields in the list. A subtotal contains all values of a field that are assigned to a particular control level, that is a particular sort string.

Delete those subtotals that you do not need using the trash can icon.

The list displayed below list displayed below is sorted according to the fields Airline ID and Flight connection code. The subtotals are created and displayed accordingly.