OK, you change this while I was responding. But in both cases, neither the original version nor this new pretty printed version is valid JSON.
But assuming that it will work in OH with the escaped double quotes, your JSONPATH has given you exactly what you’ve asked for, the element “value”'s first element of the outer array and the third element of the inner array. The third element is, as you can see from the pretty print:
The escaped double quotes (i.e. \") make that not valid JSON. In fact, the fact that the whole thing is in double quotes makes it not valid JSON. It’s a String of a JSON. I double JSONPATH will be able to handle that. But if we assume it could work, you need to tell it which element you want.
$.value[0][3].currentTemp
That almost certainly won’t work though because it’s not valid JSON so you’ll have to extract the value some other way, such as in a rule or using the REGEX transformation.