As explain over here https://blog.espressif.com/matter-device-to-device-automations-bdbb32365350,
how we can bind two devices to each other using the binding cluster. And then two devices can talk to each other without the app? This binding should happen on Matter Fabric, and it should not be dependent on the mobile application.
like, once I bind both devices, it should run independently. for example, I have two matter enable devices at my home, one is a thermostat which measures the current room temperature, and if my room temperature goes beyond 35°C (which is quite normal in India ) then my matter fabric or some Automation logic will start Air Conditioning in my home and try to cool-down my room temperature.