Hi Bastian,
If you want get DP2 data only in the report.Then you need to fallow below steps.
After merging of the DP1 and DP2 objects.You will see like.
Company (DP1.Company , DP2.Company)
Company (DP1.Business Unit , DP2.Business Unit).
And i think you are displaying Company and Business Unit of Merge dimention.In this case here full outer join will form and displaying all the records from DP1 and DP2.
In your case you need to use DP2.Compay,DP2.Business Unit objects and measure value in the displaying section.
Regards,
Pulla Reddy