What is a scope of analysis?

The scope of analysis for a query is extra data that you can retrieve from the
database to give more details on the data returned by each of the objects in a
query. This extra data does not appear in the initial result document, but it
remains available in the data cube, so you can pull this data in to the report to
allow you to access more detail at any time. This process of refining the data
to lower levels of detail is called drilling down on an object

In the universe, the scope of analysis corresponds to the hierachical levels
below the object selected for a query.

You can set this level when you build a query.

You can also create a custom scope of analysis by selecting specific
dimensions to the Scope of Analysis pane.

For example, a scope of analysis of one
level down for the object Year, would include the object Quarter, which
appears immediately under Year.