For now highcharts editor only allow simple breaks (and there is a bug in this configuration see (https://github.com/highcharts/highcharts/issues/6101)

Woud be nice to be able to configure advanced breaks too as mentionned hrer : http://jsfiddle.net/gh/get/jquery/2/highcharts/highcharts/tree/master/samples/highcharts/axisbreak/break-visualized/

Simple breaks are of little use as breaks are not visible in the chart and it is a cause of misunderstanding