title: Leaflet: How to create a group layer that shows all other layers?
body: <p>I created the following script but it won't show both layers. If i delete the single groups ("commerciele parkeerplaatsen" and "rodents") and only leave the "both" group it does work.</p>
  
  <pre><code>var CommercialParkingSpots = L.geoJson(CommercialParking,{
      onEachFeature: MakePopupWindow  
  })/*.addTo(map)*/;
  
  var Rodents = L.geoJson(rodents,{
      onEachFeature: MakePopupWindow2  
  })/*.addTo(map)*/;
  
  var both = L.layerGroup([CommercialParkingSpots, Rodents]);
  
  var overlays = {
      "commerciele parkeerplaatsen" : CommercialParkingSpots, 
      "rodents" : Rodents,
      "both" : both,
  }
  
  L.control.layers(null, overlays).addTo(map)
  </code></pre>