I could be wrong but I think that is one of the limitations of Secondary data sources: You don't see the data when you go to view underlying data.
Thanks for the quick reply Hope
I just had a look at that link you sent. I am a bit unsure of what they mean with their resolution? Do you understand this?
As a workaround, add the primary blended dimension to the view.
Afraid not. I don't feel like I've ever found a good workaround in my work. Sometimes you can promote a field from the Secondary source to the primary source. But if you are working with data that is updating you then have to remember to keep manually accounting for new information in the secondary set. If you're working with a one time pull of data then it might work better.