Grouping Legends in Highcharts
I know this is an old issue, but setting showInLegend on your series, will work, and seems the easiest way.
showInLegend: false
Eg:
series: [{
name: 'John',
data: [5, 3, 4, 7, 2],
stack: 'male',
showInLegend: false
}
Based on the reference example you linked to, you can do this with the new series 'linkedTo' property in version 3.
http://api.highcharts.com/highcharts#plotOptions.series.linkedTo
updated example: http://jsfiddle.net/jlbriggs/6gw5P/2/
linkedTo:':previous'