The voicemail system has an option that allows callers to press 0 and jump out of a voicemail greeting back to some globally defined operator. This global operator needs to be setup by support, but once configured it can be overridden per user in the user extensions. For example, lets say you have an executive that wants any caller reaching his voicemail to be able to press 0 to ring an assistant. You can do this by editing the executive extension in the communications manager portal.
1- Login into the PBX portal as an admin.
2- Go to user extension page and select the pencil for the extension you want to edit:
3- Select the "Advanced Settings" tab.
4- At the bottom of the "Advanced Settings" tab, select the extension you want to set as the Operator's extension.
5- Finally click the save button to save the changes and it will be immediately applied the new setting.