List event subscribers using views (or whathever)

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.

I'm capable to do such a thing with the subscription module but i don't want to install both modules and i guess OA2 is capable to do the same thing with it's base modules.

Thank you in advance

Best regards