Sharing dataset between domains

Hi. I don't think you can from Power Bi directly. You providers should give access to sources in order to combine your data. However I'm a Bi Provider too. Let me tell you how we solve this. We advice the customer or partner company (the one you are building stuff) to own their data. This means having their own power bi licences. That way everything is created with their domain and you can combine all data involved in their company. Power Bi will let you combine datasets with Composite feature or if you build dataflows in the same tenant you can use them both too.

That's a start. However we don't do that too much. We usually suggest building a data warehouse that should keep the source of truth of every analytics development like a Power Bi report. If the company builds a warehouse you shouldn't have this problem at all ever again.

I hope that make sense.