One option is to use CB Query Field and simple query the database for that information. Then display it on a custom page (e.g. maybe an article with CB Content Bot). Another is a userlist setup to filter users to your plan so it only shows users with an active or expired plan (can be specific or any plan). Then there's CB Auto Actions and a Code action with Method set to PHP where you could use CBSubs API to get that information, but you'd need to be pretty familiar with CB Auto Actions, PHP, and CBSubs API to do that. Userlist usage is by far the easiest to accomplish using an advanced filter. Example as follows.
Code:
( ( SELECT COUNT(*) FROM `#__cbsubs_subscriptions` AS sub WHERE sub.`user_id` = u.`id` AND sub.`status` = 'A' ) >= 1 )
The above should show any user with an active subscription of any kind for example.