In the editor place a Zeus "Game Master" module.
Create a game logic virtual entity "Zeus (BLUFOR)" and assign it as the owner of the game master module.
Place any OPFOR unit and make it playable.
Export to multiplayer.
Have 2 players connect one in the BLUFOR Zeus role and one in the OPFOR role.
Have Zeus place a marker on the map.
Check to see if the OPFOR player can see it.
Rinse and repeat with any combination of Zeus and Player faction combination.