While you can link multiple cameras to one monitor, unfortunately each camera can only be registered to one monitor at any given time. In other words, with the MBP36, it is not possible to have two monitors linked to the same camera at the same time.
The MBP160 is a system that has 2 parent units linked to one camera. Another option may be to move to a WiFi video monitor system which allows a camera to be viewed securely on multiple smart phones/devices; Blink1, Focuss66 and MBP85Connect are among Motorola Monitor systems with this capability.
For more information please click on Hubble or Monitor Everywhere and you will be rerouted.