Controlling 1 object from another

programming flash
1

Hello, this is the problem.
Im making tile-based game in as3. I have hero class. He needs an access to tile objects, but I just cant do it. All objects are made from document class constructor. In hero class I did this to reference the main stage:

public class Hero extends MovieClip
    {
        private var mc_stage:Stage;
        public function Hero(stageRef:Stage)
        {
            mc_stage = stageRef;
            trace(mc_stage.tile0_0.walkable);
        }
        
    }

So when I was creating hero object, I did

new Hero(this.stage);

This referenced main stage to hero class, but how can I get other objects from stage?

Tracing gives me this error:
1119: Access of possibly undefined property tile0_0 through a reference with static type flash.display:Stage.