If you have multiple air conditioners in different rooms, you will have to install and configure one Smart AC Controller per air conditioner.
The Smart Controller communicates with your AC through infrared technology. This technology does not pass through walls.
Once all your Smart Controllers are installed, you can control your whole system with one app: Home + Control.
Specific case:
One Smart AC Controller can control two AC units simultaneously, if and only if they are located in the same room and are the same make and model. Please note, you will need to follow the recommendations for the physical installation and apply them to both your AC units in this specific case.
Updated