{
    "responses": [
        {
            "annotations": [
                {
                    "description": "Eiffel Tower",
                    "score": 0.714323,
                    "boundingVals": {
                        "vertices": [
                            {
                                "x": 213,
                                "y": 813
                            },
                            {
                                "x": 332,
                                "y": 813
                            },
                            {
                                "x": 332,
                                "y": 2183
                            },
                            {
                                "x": 213,
                                "y": 2183
                            }
                        ]
                    },
                    "locations": [
                        {
                            "latLng": {
                                "latitude": 48.858461,
                                "longitude": 2.294351
                            }
                        }
                    ]
                }
            ]
    ]
}

rstResponse.RootElement := 'responses[0].annotations[0].boundingVals.vertices';
  x := VarToStr(MemTable.FieldValues['x']).ToInteger;

rstResponse.RootElement := 'responses[0].annotations[0].locations.latLng';
  lat  := VarToStr(FDMemTable.FieldValues['latitude']);

rstResponse.RootElement := 'responses[0].annotations[0].locations';
  s  := VarToStr(FDMemTable.FieldValues['latLng']);