You customize the service selection and time range from the Summary view.
Under Service Selection, the two options customize the Summary view as it relates to the clusters or servers that you want represented in the two charts. You can change both the cluster from which to view information, as well as the server. The list of choices in the Server box depends on the choice that you made in the Cluster box. Therefore, select the cluster first. The Cluster setting determines which cluster information is displayed in the two graphs. In addition, you can see an average response time over all servers within the cluster (the default), or to see details of the response times of all listeners on a specific server within that cluster.