title: Drilldown multiple levels Highchart
body: <p>We like to Drilldown on multiple levels in Highchart. Is there already an example in Highchart?</p>
  
  <p><strong>Currently used code:</strong></p>
  
  <pre><code>$(div).highcharts({
      chart: {type: 'column'},
      credits: {enabled: false},          
      title: {text: title},
      xAxis: {
          categories: [
              'Instroom',
              'Rijdend',
              'Úitstroom'
          ]
      },
      yAxis: {title: {text: ytitle}},
      legend: {enabled: true},
      plotOptions: {series: { borderWidth: 1, dataLabels: {enabled: true,}}},
      series: first,
      drilldown: {
          series: drillDownObject(second)
      }
  });
  </code></pre>