From the yellow table click on the sub report where you would like to add the account. It appears you have clicked on the Root report that contains two sub reports.
If you can only see the sub reports of Report then either click on the Nane, Description, or Folder Column titles to view all sub reports.
Changes to NV2 2.09 were added to speed up the setting of the report windows within the database explorer. See Help > Manual > Appendix A > 2.09.0.20070918
for more information on the changes and updates to 2.09.