Which friends appear in the chat sidebar? Can I add specific friends?
The friends that show up at the top section your chat sidebar are people you’ve interacted with frequently or recently on Facebook.
You can't add or remove friends from this top section, but it will update dynamically as the people you interact with changes.
Scroll down your sidebar to see the rest of your friends who are on chat. To find someone quickly, you can search for them by entering their name into the search field at the bottom of your sidebar.