Despite missing boss/secretary feature in 3CX PhoneSystem, found in most traditional PBXs, it is more or less possible to implement it, using 'Exception forwarding rules' in extension setting in 3CX. For the purpose it is necessary to create a queue for each of the 'bosses', having as members 'secretary' extension(s) and 'boss' own extension (if he/she wants to receive calls for some reason). Normally during office hours 'secretary' should be logged-in, and 'boss' not into queue using trivial queue settings. In extension settings for 'boss' extension(s) is necessary to define exception forwarding rule, excluding all extensions, which are allowed to ring 'boss' directly, like: You may apply this rules for office hours only, log-in/out secretary automatically, based on office hours, etc. This rule implies for internal calls only, for external calls is necessary to set inbound rule to corresponding 'boss' queue. Secretary may transfer calls to boss only in 'attended' mode, otherwise the call will return again to queue. Hope sharing this experience is useful for PBX implementers.