Right i can see we've misunderstood each other. I wasnt saying add what i put in a groovy step (although you can). All your responses are json and they all have escaped json in an eventmessages object...right?
As this escaped json is going to occur for all your responses im guessing i said use an events handler instead. Thst is, click on the Events button below the maintoolbar (next to Preferences button), click on the green plus and select RequestFilter.afterRequest.
Then add the code i gave you in the input field below. What this will do is alter the response for every request in your project so youll never get escaped json in your responses.....so you wont need any further groovy allowing you to rely on the OOB functionality to assert and property transfer.
Im typing this out on my phone so i cant see your last post but i remember you having an import declaration and another line where you'd parsed the response that you dont need with the event handler content.
Home in 20mins
Cheers
Rich