How to close Facebook message notifications?

[Broomstick]

I don't want a particular message to keep notifying me, because it's a group chat and my friends keep chatting with each other. I don't want to leave the group because it's a leadership group, but them just talking about random stuff is really annoying cause I keep getting notifications. How do I turn off notifications for a particular message?
It's a facebook message notification, not the normal notification, there is no [x] button.

[Daniel]

Where the Notification is You Will See a X That Says Turn off Click on That And you Should Be Able to Turn That Off

[Jim]

Go to the Facebook page. You'll probably see a Following button with a checkmark in it. Click that button and the notifications should stop. This does not unsubscribe you from the group.

[DinDjinn]

Or, you could just mark them as spam or junk in your email inbox, and not see them again. You could still go to your facebook account.