Released in Tableau 2018.3, the set actions feature extends the interactivity in Tableau, allowing for deeper, more diverse comparisons through user selections and opportunities to see your data in a new light.
Now you can provide richer analysis, more flexible exploration, and simpler user experiences for your stakeholders. Bethany Lyons, Product Manager at Tableau writes an excellent introduction on how to bring powerful new comparisons to viz audiences with set actions.