Drilldown Series or Categories

HTML

<script src="https://getfirebug.com/firebug-lite-debug.js"></script>
<script src="https://code.highcharts.com/highcharts.src.js"></script>
<script src="https://code.highcharts.com/modules/drilldown.src.js"></script>

<div id="container" style="min-width: 310px; height: 400px; margin: 0 auto"></div>

JavaScript

Highcharts.chart('container', {
  chart: {
    type: 'column',
    events: {
      drilldown: function(e) {
        // If clicked on axis title: drill down into product group
        if (e.category !== undefined) {
          if (e.points.indexOf(e.point) == 0) {
            //alert('drill down into ' + e.point.category);
            console.log('drill down into ' + e.point.category);
          }
        } else if (e.point) {
          // If clicked on the column or the data label: drill down into countries
          //alert('drill down into ' + e.point.series.name);
          console.log('drill down into ' + e.point.series.name);
        }
      }
    }
  },

  xAxis: {
    categories: ['cat a', 'cat b', 'cat c']
  },

  plotOptions: {
    series: {
      stacking: 'normal',
      dataLabels: {
        enabled: true
      }
    }

  },

  series: [{
    name: 'Europe',
    data: [{
      y: null,
      name: 'cat a',
      drilldown: false
    }, {
    	name: 'cat b',
      y: 200,
      drilldown: true
    }, {
    	name: 'cat c',
      y: 200,
      drilldown: true
    }]
  }, {
    name: 'Asia',
    data: [{
      y: 0,
      name: 'cat a',
      drilldown: true
    }, {
    	name: 'cat b',
      y: 100,
      drilldown: true
    }, {
    	name: 'cat c',
      y: 75,
      drilldown: true
    }]
  }]
});