Sankey diagrams work best with a data set that shows a before and after state, or relationships/transitions between two or more categories. To learn more about what types of insights work best with a Sankey, see Tableau Blog: Exploring Sankey and Radial Charts.
To build a viz with this extension, assign two to five categorical dimensions to the Level encoding box and assign one or more measures to the Edge encoding box.
This viz extension is created and hosted by Tableau and makes use of Tableau interactivity behaviors. This version does not yet support formatting and keyboard navigation. Viz Extensions are currently available only in the Tableau Cloud Beta Preview, as a part of the web authoring experience.