Enrique,
While the Pusher app store documentation describes a global notification, you could use a separate persistable object for each user (or groups of users, perhaps by user role or some other grouping) so that you can send separate notifications to different users or groups of users. For Instance, if the persistable object that Pusher depends on is sourced via microflow on a page, you could return an object of which I am the owner, or a different object for each user role. Then when you need to send a notification, you can retrieve the appropriate object(s) and use them for notifications.
Hope that helps,
Mike