You would want to open the network policy> Go to the Wireless Networks tab> Check the box next to the SSID You want to remove> Click on the trash can icon towards the top of the page. This will remove the SSID from this network policy, but it won't delete the SSID object from your HiveManager so you can re-add it wherever you'd like in the future.
If you want to delete the SSID entirely from the HiveManager, you would want to go to Configure> Common Objects> SSIDs (on the left hand side menu, under the heading "Policy"> Check the box next to the SSID you want to delete> Click on the trash can icon towards the top of the page. This will delete the SSID object so you'd have to rebuild it from scratch in the future.
Does that answer your question? These instructions assume you are using HiveManager (formerly NG, cloud.aerohive.com), if you are using HiveManager Classic (myhive.aerohive.com), please let me know and I will provide instructions specific to that platform.
