According to the BACnet protocol documentation:

Defines a standardized object whose properties represent the externally visible characteristics of a group of lifts or escalators (a group being defined as those lifts or escalators controlled by a single supervisory controller).

Objects of type elevatorGroup have the following properties:

•description

•groupId

•groupMembers

•groupMode

•landingCallControl

•landingCalls

•machineRoomId

•objectIdentifier

•objectName

•objectType

•profileLocation

•profileName

•propertyList

•tags