Group Chat, as the name suggests, enables users to chat in small groups. It is a kind of chatroom which can be created by non-admin (regular) users. If a user wants to chat with 4 of his friends, not in public chatroom, but privately, he/she can create a group chat by inviting all 4 of his/her friends. Nobody else can see this chat without an invite.
1) You may start a group chat by click on Add User icon within a direct conversation window as shown below:
2) Next click on "Add participants" button
3) Select any user to add to the group conversation
4) A separate chat window will popup where you may start your group conversation
5) You may again click on Add User icon to view the current participants in the group chat. Also it can be used to add more users to the group conversation as show below:
Please note that this feature is available from Professional Plan Onwards.