My question is actually about a problem with the G+ for YouTube. Formerly, I have received the notifications over email and could go to my comment in YouTube to respond. Now, you can respond right in the G+ notification system and YouTube still allows you to link to the comments under the video, but I see no such link provided to you by G+ notification system.
All I see is a link like Shared publicly - Yesterday 6:27 PM next to the top comment in the G+ notification, which I can click, but it does not bring you to the comment in YouTube. It brings you back to the plus.google.com, to a page called "Only visible on http://www.youtube.com/watch?v=G5Dv9uLRLJs". What does that mean? I am especially puzzled after I have located that discussion thread manually under the YouTube video and it does not show my comments when I am logged out.