Groupings may be created by dragging any master column header to the Group Drop Area.
In this example I'll create a group by "Creator" by dragging the Creator header and dropping where shown.
Creator becomes a grouping column as shown below.
Multiple columns may be added to the Group Drop. Grouping may be rearranged by dragging columns around on the Group Drop area.
Remove a grouping by hovering the group name tile and clicking the X.