Many-to-Any Relationships

[BiBo]

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How can I reference data across documents and workspaces?

I have 4 workspaces, as I divide between my clients. In my master workspace, I use common data (eg Country list). How can I use that data as Reference in a document in a different workspace? Currently I maintain the same table copied in different workspaces/documents, but would be good to have a single source of truth to avoid mistakes.

If i have 3 different tables (with columns):
ProductType1 (UUID, ProductName, PartNo, ColumnsN)
ProductType2 (UUID, ProductName, PartNo, ColumnsM)
AllProducts (UUID, ProductName, PartNo)
In each ProductType table I configure PartNo and ProductName for this product type.
Then I need to union all the data from the table ProductType1 and ProductType2, while making changes to any ProductType tables need same result in AllProducts table.

This can be done on the basis of one table ProductType (UUID, ProductName, PartNo, ColumnN, ColumnsM) but formula for calculate ProductName and PartNo based on ColumnsN for ProductType1 and ColumnsM for ProductType2.
That is, if I have N ProductType i need N conditions for formula calculated ProductName and PartNo.