OLAP and Tabular Sources
To use an MS OLAP or Tabular cube as a datasource, go to the Data Flow, add your datasource and select the required tables as usual.
You must then connect an SQL Server as the target.
When you move to Data Model, select Tabular as the model target in order to build a tabular model.
To learn how to query OLAP and Tabular data models in Discover, click here.