Just head to your Google+ Settings page to tweak this preference. You’ll see it under “Who can interact with you and your posts”. Just change the “Who can send you notifications” preference to fit whatever group of people you want — it can be “anyone”, a specific circle or group of circles, or individuals. Google’s rolling this feature out slowly, so if you don’t see it right now, check back soon to enable it. Hit the link to read more.
Now you can decide who can notify you on Google+! [Kathleen Ko]