Add a dataset to the project, which uses two non-linked tables, e.g., the "Employees" and "Products" tables of the sample Northwind database.
Make sure that data source of the report itself is not assigned. If it is not empty, you should manually reset the report's XtraReportBase.DataSource and XtraReportBase.DataMember properties, since similar properties are to be assigned individually for the DetailReportBands.
To add a DetailReportBand instance, right-click anywhere over the report's surface, and select Insert Detail Report | **Unbound** in the invoked popup menu.
Next, assign a data source to the created Detail Report. To do this, click the Detail Report's smart tag, and in the invoked actions list, set the DataSource property to the required data source.