he Subscription-based Notification plugin allows Service-now users to manage their subscriptions for any notification in the system. It also allows users to subscribe to particular Configuration Items in your CMDB that they may be interested in.
As an administrator or process owner, it may be necessary for you to be able to view or report on which users have subscribed to updates for a particular configuration item. You may also want to see what configuration items a particular user has subscribed to without opening up their subscriptions page.

Fortunately, this information is all contained in a table that you can show on both a configuration item form and a user record. The name of the table is ‘Notification Messages’ (cmn_notif_message). Since this table contains all notification subscriptions for your system, you’ll want to filter the list so that it only shows you records with a ‘Notification Message’ value of ‘CI Affected’. You could also personalize the related lists for either table and add the ‘Notification Messages -> Configuration Item/User’ related list to your form.