You can cancel grouping records by using either the grid pop-up menu commands, or the Group Panel, or the Grouping tab of the Customize View window.
To ungroup records using the pop-up menu command:
Right-click anywhere in the grid and choose Group > Ungroup from the pop-up menu. This will remove all grouping from the grid.
To ungroup records using the Group Panel:
Choose which grouping level you want to remove, drag its corresponding column heading from the Group Panel, and drop the heading between the column headings where you want it to appear. A green double-arrow will indicate the place where the column will be inserted.
To ungroup records using the Grouping tab of the Customize View window:
Right-click anywhere in the grid and choose Customize View from the pop-up menu.
In the Customize View window, click the Grouping tab.
Choose one of the following:
If you want to remove some specific grouping levels,
double-click the first corresponding field in the Group by These Fieldspane . Repeat this action for all grouping levels, if needed.
If you want to remove all grouping from the grid, click Remove All.