Click on Edit on an SSID row to display the Edit SSID screen. These are the same fields you consulted or configured in the Select an SSID section from the central pane of the Policy > Policy Hierarchy screen. Now these fields are applied to a new SSID you have selected from the SSID Policy screen.
WDS - The bottom of the screen has a toggle to select whether this access point is part of a Wireless Distribution System (WDS). A WDS is a group of access points associated together in such a way as to expand the range of the signal availability.
The Edit SSID page can also be used to configure the RADIUS Accounting Server. This configuration option is available on the Policies > SSID Policies > Edit > SSID Edit screen.