twoviews.js

require([
  "esri/Map",
  "esri/views/MapView",
  "esri/views/SceneView",
  "dojo/domReady!"
], function (Map, MapView, SceneView){

  // one map, 2 views
  var map = new Map({
    basemap: "streets"
  });
  var s_view = new SceneView({
    container: "sceneDiv",
    map: map,
    scale: 240000000
  });
  var m_view = new MapView({
    container: "viewDiv",
    map: map,
    zoom: 5,
    center: [-118, 35.5]
  });
});