Two floor building model using UNITY with ROS robot and elevator

Hello

I need someone who can create a UNITY model for a ROS robot.
The mode will contains of two simple floor building, where the robot move between these floor using an elevator.
The floor design is simple but the important part is that the robot can move from the first floor to a specific place in the second floor using the elevator

Please do not bid if you not already have experience with UNITY and ROS