Using the brilliance of Ian Baldwin (https://www.theinformationlab.co.uk/2018/03/09/build-sankey-diagram-tableau-without-data-prep-beforehand/ ) I was able to create a Sankey chart using data posted on Tableau Server without any manipulating of the data. Then I got ambitious and wanted to create a decision tree similar to what Olivier Catherin has done here https://community.tableau.com/thread/154623 I was finally able to create the simple curves,

but unable to create the full model with the polygons, as shown below. any suggestions most welcome.

The attached workbook mimics Ian's sankey polygons on the first tab and then the decision tree on the second tab (Look Ma, no data prep!). The third tab shows my lack of progress on Curve A of Olivier's post. Thanks, Nicole