How to add an offset for specific data bars in angularjs d3

Question

Is there any way to add an offset for data, like in image below? Thanks in advance

Here is my simple multibar chart controller, I think it has to do something with y function, but it requires number to be returned, not range

.controller('multiBarHorizontalChartCtrl', function($scope){

    $scope.options = {
        chart: {
            type: 'multiBarHorizontalChart',
            height: 450,
            x: function(d){return d.label;},
            y: function(d){return d.value;},
            showControls: true,
            showValues: true,
            duration: 500,
        }
    };

    $scope.data = [
        {
            "key": "Series2",
            "color": "#1f77b4",
            "values": [
                {
                    "label" : "Group A" ,
                    "value" : [10, 15],
                } ,
                {
                    "label" : "Group B" ,
                    "value" : 11
                } ,
                {
                    "label" : "Group C" ,
                    "value" : 13
                }
            ]
        }
    ]
})