Is there a way to receive notifications when somebody modifies a content in a group I belong to?

As I understand, elgg notifications are received when:

1. My own content is modified by someone else
2. A friend of mine is creating new content
3. Someone creates new content in a group I belong to.

But there is no way to receive a notificacion when other's content is modified in a group I belong to.

I have been searching for a plugin to achieve this without success.