JSON expression instead of many change nodes?

Great! Just to let you know, your change nodes would not have worked the wScreen Shot 2020-08-03 at 3.56.23 PM ay you had them.

Rule 2 will set msg.payload to the contents of msg.payload[1][1]
Rule 3 wants to set msg.payload1 to the contents of msg.payload[2][1] but msg.payload has been overwritten by the contents of msg.payload[1][1].

To do this you could do something like this:
Screen Shot 2020-08-03 at 4.00.31 PM