drupal7 open atrium notifications views events

Hello everyone,

I'm building an intranet for my company using Open Atrium and i need a way to let a certain group (event managers) to see a list of content (calendar event in this case) subscribers in the event page.

I'm trying to accomplish this using Views but i cannot figure out witch elements use (there is no subscriptions structure element in OA)

Since I'm relatively new to Drupal and totally new to Notifications i need to being pointed in the right direction for the best practice to do such a thing.