As you can see, the set of the bands differs from “classic” schema that is used in the ReportBuilder (here and after – ReportBuilder 4.x). On this schema, the report itself has a dataset and it presents the first data level. The second data level is formed by the detail band. In other words, classic schema allows you to create master-detail reports. If you want more detail levels, you obliged to use sub-report which is actually another report placed on the separate page. Sub-report also used for master-detail-detail reports.