By default, the drill down operation drills down to the next generation. In the Data Options dialog box, the Drill Down Behavior section allows you to specify the drill down behavior to drill down to:
of the selected member in the grid or chart. Once the option is set, subsequent drill down operations will reflect the drill down behavior you specified.
To specify the drill down behavior,
The next time you drill down, the drill down behavior will reflect the option you selected. This behavior does not change until you specify otherwise or exist the application.