Sorting grouped records in a report

Sorting grouped records in a report

Currently, the default sort order for records works extremely well for me. I guess this is based on displaying records sorted on ID with latest first.

Now, when I group my records by a text field from the parent table (which summarises the parent record), I am forced to sort A>Z or Z>A (in the Grouping box) on that text field but I really want to sort by the parent ID field Z>A but I don't want to display the parent ID.

Is there a solution to this?