Hi
Thanks for your inquiry. Unfortunately there is no "one step" way to populate a document with data that has parent-child relationships. Mail merge regions can only process one data table at a time.
But you can generate such reports by performing mail merge several times and building up a resulting document from several documents or fragments. The Product Catalog and Sales Invoice samples in the demo project supplied with Aspose.Words demonstrate the suggested techniques.
Hope this helps.
Best regards.
Alexey Noskov
Developer/Technical Support
Aspose Auckland Team