Notify group using share>notify feature

I was just about to post this as a feature request too.

It would be very helpful so as to push out a notification of a specific post of a topic without setting the whole group to watching for the Topic (via either a @mention or tag watching)\

At the moment my rather ugly workaround is to create a new topic with watch first post active for the relevant users and then moving it after a short while to the Topic that it should be living in.