Enable the Channelmembers module.
When set to true, if the channel is mapped to a group name, the channel manager will not be able to add/remove users manually. Only alternative option would be to change the role of the users that were added through the synchronization process.
(default false). Used to support use cases where the offline synchronization process controls both the users and their role in the channel and prevent the channel manager from overriding those settings via KMS.
Add member guidelines text when creating/adding member to channel. Use [b]foo[/b] - for bold, [i]foo[/i] - for italic. The entire list is here
Allow the channel manager to set a group name for offline sync.
Group Users - Allow detaching users only from associated groups.
Group Users - How should User-Groups show in members list.
When enabled, the user suggestions in “add member to channel” will also find groups.
When enabled, the remove and edit group option in the channel will be enabled.