The Comments section is available at every level: Global, Group/Regional, and Site; and can be viewed from every tab. It is always located just above the Collaborators list. It is important to note, these comments are specific to the level in which they are made, but not a particular tab. So, if a comment is made in a site within the Accounts tab, that comment can also be viewed in the Notifications tab or Analytics tab.
A comment can be viewed from its specific location within a site or group/region, but you can also view recent comments in the order in which they were created from the Notifications section on the Dashboard.
If you would like to make a note about something on a site or group/region for others to see, scroll to the comments section and start typing your message into the input box.
Once you click Post, the comment will become visible to all users with access to the site or group/region. The comment will also appear on those users' Notifications Feed.
You can reply to previously posted comments by typing into the Reply input row inside of the comment box.
To remove a comment or reply you have made, simply click the x button on the corner of the comment box. This will remove the comment from the group/region or site and also from all users' Notification Feeds.