How to include related records in a report
You can show values of attributes of business objects related to a particular business object on a report. For example, if a PurchaseOrder object is related to an OrderLineItem object via a multiple relationship you can show which order line items are related to a particular purchase order on the report.
To include values of attributes of the related object in the report you have to define a sub-report element in the report. The sub-report element must refer to the report showing the instances of the related object and the query of the sub-report element must find the related objects. For example:
FIND OrderLineItem WHERE OrderLineItem IN PurchaseOrder.MyLineItems
See also the “Editing Sub-report/Sub-presentation Element” section.