Tableau has rich and flexible semantics for customers to answer sophisticated analytic questions. With the recent release of Multi-fact Relationship (MFR, aka "Shared dimensions"), we are building on the Tableau data foundation to delegate semantics to other semantic layers. We will discuss the concept of aggregate awareness and how Tableau semantic stack will federate semantics similar to what Tableau has pioneered in our federation of connectors to different databases. Tableau continues to be the "Switzerland" of data, be they as unaggregated in relational tables or as aggregated metrics, and they can be combined and used to answer analytic questions.