Hi,
You can build on OVS based on BO2. Then you modify BO2 to accept the UserID as query parameter. For this, you must add the UserID as parameter in the Inport and add it as criteria to the query.
When binding the OVS to a screen based on BO1, you can bind the import parameter UserID you added to the OVS to the UserID in BO1.
Does this make sense for you?
If you check some of the standard OVS screens, you can see how this is done. The BusinessPartner OVS for example takes a few arguments.
Best Regards,
Stefan