Configure as in 2 above. Add an additional subreport to the detailband. Set subreport.ShiftRelativeTo property to the point to the first subreport. Connect the ChildReport's DataPipeline to the detail data.
When Report.AutoStop is set to True, the Report will print a single detail band.
When Report.AutoStop is set to False, the Report will print detail bands until instructed to stop. You can control when the report stops by setting the Report.PageLimit property or by calling Report.DataTraversalCompleted method. Otherwise the report will never stop.
Additional Notes:
Check out the RBuilder\Demos\Reports\Demo.dpr project. Reports 0071, 0072, 0073 show examples of master w/mutliple detail style reports. Number 0072 has two detail reports.