Hi Andrew,
The best way to handle this if you want to stay in the same flow would be to Ask A Question immediately after the card. The shortcut button being pressed then becomes the answer to the question as opposed to triggering a new flow. You can then continue in the flow and if required use the answer to the question to shape the direction the user takes in the flow by going to a label etc.
The code service would be the best option to allow you to navigate through your JSON object and return the required node to add to the card.