This is not a clone. It's a new request I had to add, since the old was closed with a technically fault answer. By technically fault I mean possible, but in real scenario unusuable.

F.e Jasper's SubReports have a property called DataSource. The sub-reporst uses this dataSOurce for rendering it content. The DataSource is always set on the Main report. Everything via designer, no need for coding. So I'd like to see such a possibility in telerik reports.

The suggested solution - with the bindings http://www.telerik.com/forums/how-to-bind-the-datasource-of-a-subreport-in-the-designer is technically wrong. It assumes that the child report knows at which level he resides inside the main report. The child report (or it's binding) should have not such info embedded. Let's see on an example. Let's have a dataset:
User.Address
User.PostalAddress
User.Wife.Address
User.Wife.PostalAddress

The dataset should be bound to the main report. The main report should have 2 sub-reports (address and postal addres). It can have an another sub-report (for wife data) which then would again have 2 sub-reports inside for addresses.

Using the technically wrong solution, the addresses for the main user should have a binding expr. like: =ReportItem.Parent.DataObject.xy and the wife's addresses have like: =ReportItem.Parent.Parent.DataObject.xy

There is a big problems with such a binding: the child must know the hierarchy of the data.

The technically clean solution is to have a dataset assigned to the main report. When adding a sub-report to the main report, via binding we should set the new data-source for the sub report. something like: MainReport.Data = dataSource. SubReportAddress = dataSourceOfTheCurrentReport.Address. SubReportWife = dataSourceOfTheCurrentReport.Wife and inside "wife report" the next sub-report for address address should have a binding again like: SubReportWifesAddress = dataSourceOfTheCurrentReport.Address