HighCharts - Single legend for two columns in a Stack Column chart - highcharts

Question

I have four stack in a Stacked Column chart: "One Completed", "One Pending", "Two Completed", "Two Pending".
By default, I have four legends for these stacks.
What I want is to have two legends: "One" and "Two". Is it possible using Highcharts?
Edit:
Added code. Some of text/logic are removed. Most of the styling is what I found on Internet somewhere.
Highcharts.chart('', {
chart: {
type: 'column',
},
title: {
text: '',
},
xAxis: {
categories: c,
labels: {
y: 40
}
},
yAxis: {
min: 0,
title: {
text: ''
},
stackLabels: {
enabled: true,
verticalAlign: 'bottom',
crop: false,
overflow: 'none',
y: 20,
formatter: function () {
return this.stack
},
style: {
fontSize: '9px',
color: (
Highcharts.defaultOptions.title.style &&
Highcharts.defaultOptions.title.style.color
) || 'gray'
}
}
},
credits: {
enabled: false
},
legend: {
align: 'right',
x: -30,
verticalAlign: 'top',
y: 25,
floating: true,
backgroundColor: Highcharts.defaultOptions.legend.backgroundColor || 'white',
borderColor: '#CCC',
borderWidth: 1,
shadow: false
},
tooltip: {
formatter: function () {
//custom logic
}
},
plotOptions: {
column: {
stacking: 'normal',
dataLabels: {
enabled: true
}
},
series: {
cursor: 'pointer',
events: {
click: function (event) {
//custom click to filter logic
}
}
}
},
series: [{
name: 'One Pending',
data: one_series_pending,
color: '#7cb5ec',
stack: 'Pending'
}, {
name: 'One Completed',
data: one_series_completed,
color: '#7cb5ec',
stack: 'Completed'
}, {
name: 'Two Pending',
data: two_series_pending,
color: '#434348',
stack: 'Pending'
}, {
name: 'Two Completed',
data: two_series_completed,
color: '#434348',
stack: 'Completed'
}]
});
Sample chart:
I want single legend for same color(two stacks)

Answer 1

You can link one series with another and have one legend item for them by using linkedTo property.
series: [{
name: 'One Pending',
data: [9, 5],
color: '#7cb5ec',
stack: 'Pending'
}, {
name: 'One Completed',
data: [6, 2],
color: '#7cb5ec',
stack: 'Completed',
linkedTo: 0
}, {
name: 'Two Pending',
data: [35, 5],
color: '#434348',
stack: 'Pending'
}, {
name: 'Two Completed',
data: [3, 0],
color: '#434348',
stack: 'Completed',
linkedTo: 2
}]
Live demo: http://jsfiddle.net/BlackLabel/eh5m10q9/
API Reference: https://api.highcharts.com/highcharts/series.column.linkedTo