Automatic notification to the members of a group

Hello again.
Before starting, I would like to comment that I have been working with my forum on Bbpress and buddypress for a couple of years now.
More than 10 years ago I was managing the same community under a PHPBB3 forum, but we wanted to move to WordPress and Bbpress.
Actually, I installed buddypress only for the management of users, groups and permissions on the forums, but I have finished fed up of its complexity and unpredictable operation when managing permissions, especially for subforums.

I’ve been trying “Private groups” recently and the truth is that it’s just what I needed. It is true that I think it would be necessary to polish the massive management of the users that belong to several groups, but saving this setback is what I need.

Only missing a functionality. I know that each user can subscribe to a forum or topic, but I would like to know which plugin would work well with “Private Groups” to get the members of a group automatically notified, when in the forum where they have permissions a new one subforum, topic or answer is created.

Greetings and thanks in advance.

The page I need help with: [log in to see the link]