{
  "$schema": "https://vega.github.io/schema/vega-lite/v2.json",
  "data": {"url": "data/cars.json"},
  "facet": {"column": {"field": "Origin","type": "ordinal"}},
  "spec": {
    "facet": {"row": {"field": "Cylinders","type": "ordinal"}},
    "spec": {
      "mark": "point",
      "encoding": {
        "x": {"field": "Horsepower","type": "quantitative"},
        "y": {"field": "Acceleration","type": "quantitative"}
      }
    }
  }
}

Add facet of facet example
Add facet of facet example