If you'd like to learn more about how to use Screen Share then take a look at this tutorial. Using Screen Share, team members can coordinate directions and changes to data on a map in real time. Map Mavin's Screen Share feature allows anyone (assuming permission is given where applicable) to make a map and collaborate with other users live, with everyone in the group seeing the same screen.
To access Screen Share, head over to Map View, and click the circular green button at the bottom right hand corner of the screen (in cases where the visibility controls have been changed, the button may not appear). Once that chat window opens, click Join/Start Screen Share to initiate it or join in.