I think if you install the Hubitat app on your phones it sets up "presence" devices on Hubitat. I think you could then use Rule Machine to do If (any of phones A, B, C presence changes) and (all of phones A, B, C are not present) then close doors
There are also some apps out there that detect presence based on whether your phone is connected to your local WiFi. See: [UPDATED] iPhone WiFi Presence Sensor
