8.6.6 Expand Group & Collapse Group
If you have specified grouping conditions, the and commands allow you to expand and contract the grouped results. Before you can expand or contract information, you must first specify the groups in which you wish to group your data, as described in the 8.4.1 Group By options.
Use the command to hide the display of the query's details so that you can easily see the group totals. Then use the command to see the details again.
Using the command, you can collapse the rows until only the grand totals are displayed.
Further Information