4.2.3 Configuring privacy settings
You can specify for each group extension whether people outside of this group are allowed to take calls and whether they can see Contact Desktop notifications of incoming calls. You can also add privacy groups to a group extension, so that the members of this group can see notifications and/or pick up calls.
Adding privacy groups will not add the members of this privacy group to the group extension and thus will not receive any calls.
To configure privacy settings
You need to create privacy groups first, see 6.3 Privacy groups.