Group chat is now possible from the Odoo chat service and you can have information of members in the chat bar. All the followed groups will be available for group chat. Whenever, you need to send message to the particular group, you just have to double click on the particular group and can start the chat in that group.
Each member of that group will get message if they are online or when they will appear online.
Alternatively, you can also drag and drop additional users from your chat users list into the ongoing conversation.
Module is available on Odoo Apps Store
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