Hello,
As per my understanding of your requirement, your Main report contains a SubReport (S1) which in turn contains a SubReport(S2).
Your datasource is in form of a List of Objects in which each object further contains a list. For instance a list of category objects wherein each category contains a list of products of that category.
S1 displays the list of categories and there has to be an S2 for each category to display the list of products.
In case the above understanding is correct, my suggestion would be to create a parameterized SubReport wherein, a field in S1 can behave like a parameter for S2 and display the corresponding list.
The reports will however be unbound reports.
You may refer to the following link for information on creating a parameterized subreport at runtime:
http://helpcentral.componentone.com/nethelp/AR7Help/OnlineEn/arWLKSubreports.html
For information on using Enumerated list as datasource you may refer to the following link:
http://helpcentral.componentone.com/nethelp/AR7Help/OnlineEn/arWLKSubreports.html
Please correct me if I have missed out anything or misunderstood your query. It would be really helpful if you could elaborate your requirement a little using an example or a scenario as I would be able to provide an appropriate solution.
Best Regards,
Tuhina