title: Highcharts - How show only two series on click
body: <p>I found this example that half does what I need. I would need it to show two series, not just one.</p>
  
  <pre><code>events: {
                  show: function () {
                      var chart = this.chart,
                          series = chart.series,
                          i = series.length,
                          otherSeries;
                      while (i--) {
                          otherSeries = series[i];
                          if (otherSeries != this &amp;&amp; otherSeries.visible) {
                              otherSeries.hide();
                          }
                      }
                  },
                  legendItemClick: function() {
                      if(this.visible){
                           return false;   
                      }
                  }
              }
  </code></pre>
  
  <p><a href="http://jsfiddle.net/tK38J/65/" rel="nofollow noreferrer">http://jsfiddle.net/tK38J/65/</a></p>
  
  <p>For example: I click series 1 and I see series 1 and 2. I click series 3 and I see series 3 and 4.
  Series 2 and 4 will be hidden in the legend.
  Is it possible?</p>