There are two options. The first one would be to trigger whenever you change your category on Twitch. You'd use the Stream Update trigger and create an if/else-subaction (Core -> Logic -> If/Else) to check for:
if %gameName% Equals GameXYZ and put the action you want to run into the True Result. That action would contain all subactions to enable/disable whatever you want.
The second option is to check for when the game process starts on your PC. You'd use the Process Started trigger (Core -> Processes -> Process Started) for that. You can then specify the name within the trigger, it usually is just the name that pops up in your task manager. If there are multiple process names available, try them out one by one and see which one triggers the action. Make sure process watcher is enabled in Streamer.bot's settings, too.
Note: Some games with anticheat will prevent you from using the process as a trigger.
