C4C Report Navigation to TI

Dear C4Cers,

we have created a custom report based on a joined data source of oppi header, oppi item and account. Due to this join the report seems to have lost all "Navigation targets". How can we reinstate the link between report line and BO?

The basic view of this report shows an opportunity item enriched with header and customer details. It would be nice to jump to the opportunity and maybe even to the account from clicking on the line in the report.

Searching previous threads and blogs I could only find tutorials for navigating to other reports but not to TIs.