After you create a transformation view, you can add additional columns from the source dataset. 

To add additional columns from the source dataset:

  1. Select Transformation views from the left-side panel.
  2. Select a transformation view dataset from the list.
  3. Select Data sources .
  4. Expand the dataset menu from the Data sources panel on the right (the Primary label displays next to the dataset).
  5. Select the icon next to the column you want to add.