In Extreme Control Center
Use Control Tab
Click on Access Control Configurations->Default (if default rules are used or else other rule set)->Rules
Click on the Add button.
The following window should appear for Add Rule. Otherwise you can click on an existing rule.
Click on + button and select New
Now add information about the group you are creating
Click on the Add button
Add the detail in for the switch or switches you wish to add here, alternatively, ports or SSID's can be used via the Interface pulldown.
Then click Add
You should now see the switch added to the group. Review and then hit Save & Close
The new Rule will appear, including the location group chosen. Keep in mind, a pre-existing rule could have been altered instead.
Click Save Here, and then note the rule should have a location as a parameter in it.