Based on your comment on Tim's answer:

Yes, that would be possible, but you would probably have to introduce a third entity (if I read this correctly):

• Create a non-persistent View entity, that has two references, one to each entity
• In a microflow (where you would open this page) you would create a View object, set both references, and pass this to the page with the two data views
• Your main dataview would be the View entity as page parameter, then your other two dataviews would be get the object over a reference

If someone has an easier solution, I'd like to hear it :-)

Sure, that is no problem.

There can be only one Dataview that has a page parameter as Datasource.