How to built a report of Document flow in SAP ByDesign

Dear Community,

Our service manager requires a Sales Order Report with the Service Order and Service Confirmation Flow Document to determine the percentage of Services that have required spare parts.

I was looking for a data source to put together this report but it is not possible or there is no data source with the Document Flow.

Please looking at the screenshot screenshot-1.png of Service Request 262622 document flow I observe that the relationship exists in system but how we could extract this information into a report?

Kind Regards and thanks in advance,

Raul