Hi Christoph,
Yes when you join Data foundation field to the Attribute view, the one in the data foundation disappears and the one in the attribute view appears in the output.
In cases of Inner join or referential join, the attribute view field fulfills the need as the same value would be present in the private attribute and the attribute view attribute.
While you can re-add the private attribute joined to the attribute view by selecting from the context menu add to the Output.
Regards,
Anjali.
