Functions
The
SelectData method for the MDDataSetBW Business object executes an MDX command and creates a dataset corresponding to the MDX command.The entry parameter DataSetID must be set since several MD_COMMAND objects can be processed within a session in parallel. A client application can use the MDDataSetBW.CreateObject method to retrieve such an object handle.

You can find additional information under
The client application can use the following methods to get data as a result set:
Notes
Parameters