I posted my code to implement a C++ version of JsonPath for use with Qt 5+ QML. If you've used XPath then this should be familiar. It's XPath for JSON. QJsonPath allows selecting arbitrary subsets of a json object given a search string.
I'll be modifying the code to create a QML item in a Qt Plugin.You could then include it in your QML project without recompiling.
I've also got a JSON list model control cooking. Used together with this you can request data from an arbitrary web service, pull out a subset, and display it using the Qt controls.