The following examples show the Sessions metric graphed over the Hour of Day dimension (in the top line graph) and the same line graph with a second metric, Value per Session, added to the left axis (in the bottom line graph).
To add a new metric
Right-click an element or the label of a metric and click Add Metric > < metric name>. The metric is added below the metric that you selected originally.
To change a metric
Right-click an element or the label of the metric that you want to change and click Change Metric > < metric name>. The new metric replaces the original metric.