Top N (OLAP) 
Purpose
The Top N template is an OLAP ranking template with which you can build queries that calculate the rank of a level based on a specific measure. This template is not limited to top values, but also lets you select bottom values, independently or together with top values. This sort of query makes it easy to identify your leaders and laggards.
You should use this template if you would like to address business questions such as the following:
Who are my top ten or bottom ten customers?
Prerequisites
You have an OLAP data service configured as a BI system.
Process Flow
After using the BI Query Wizard to select an OLAP data service and the Top N template, the wizard steps you through the following process flow:
...
Result
After you have completed the wizard screens according to the process above and clicked Finish, you return to the Visual Composer workspace, where a new data service has been created with the query you have configured.
A data service created with the BI Query Wizard is configured automatically with a start input and a table view as output. These three elements together constitute a complete iView, ready for preview and deployment to your portal.
To continue working with your data service and query, see:
Example
For a complete example of using the Top N template to create a BI iView, see Example 4: BI iView.