Q: Get value from other column on the same stack - Highchart I have this stacked column chart. Demo 
        tooltip: {
            formatter: function() {
                return '<b>'+ this.x +'</b><br/>'+
                    this.series.name +': '+ this.y +'<br/>'+
                    'Total: '+ this.point.stackTotal;
            }
        },

I want when I hover the first column, it should display:
John: 3
Bob: 5
Total: 8

whatever the stack I hover on the same column, it should display 3 those values.
How to do that? My solution I've thought is get (this.total - this.y) but it doesn't show correct value.

A: The normal way to show the values in the stack is to define your tooltip as follows:
tooltip:
{
    shared:true
},

http://jsfiddle.net/RG8YT/
I'm not sure if this is good enough for what you want, as in your chart, that shows all the values, not just the ones in the stack.
There is a question here: highchart total in tooltip about adding totals to a shared tooltip.

A: In case when you would like to sum only in "part of stack", I mean left / right, you can sum elements partially.
 var indexS = this.series.index,
                    indexP = this.point.x,
                    series = this.series.chart.series,
                    out;


                out = '<b>'+ this.x +'</b><br/>'+
                    this.series.name +': '+ this.y +'<br/>';

                switch(indexS) {
                    case 0:
                        out += series[1].name + ': ' + series[1].data[indexP].y + '<br/>';
                        break;
                    case 1:
                         out += series[0].name + ': ' + series[0].data[indexP].y + '<br/>';                            break;
                    case 2:
                         out += series[3].name + ': ' + series[3].data[indexP].y + '<br/>';
                        break;
                    case 3:
                         out += series[2].name + ': ' + series[2].data[indexP].y + '<br/>';
                        break;
                }


                out += 'Total: '+ this.point.stackTotal;

                return out

http://jsfiddle.net/sbochan/3Utat/7/
