The dimensions report cuts across the hierarchical account, campaign, and ad group structure and provides alternate ways to organize performance metrics. For example, you can use the dimensions report to see the total number of actions per week that occurred last quarter in all campaigns and ad groups.
You can also segment the dimensions report for richer data. Continuing the previous example, you can apply the device segment to see device-specific actions per week in the last quarter.
Select the reporting scope by navigating to an advertiser, engine account, or lower scope.
Click the Dimension tab and select a dimension for organizing the report. For example, select Device segment to see metrics for each type of device.
Click the Segment button, which appears above the performance summary graph.
Select one or more segments and click Apply.
The reporting table displays additional columns for the segments you selected, and each row is divided into the selected segments. In addition, the Segment button above the performance summary graph displays the segment you selected.