[Solved]-How can you combine multiple graphs and control with one range selector with Highcharts?-Highcharts

all you need to do is to connect the navigator range with x-axes extremes by using setextremes method. the below example is using a navigator from highstock.

    xaxis: {
        ...,
        events: {
            aftersetextremes: function(e) {
                chart1.xaxis[0].setextremes(e.min, e.max, true, false);
                chart2.xaxis[0].setextremes(e.min, e.max, true, false);
            }
        }
    }

live demo: http://jsfiddle.net/blacklabel/4lfegyqa/

api reference: https://api.highcharts.com/class-reference/highcharts.axis#setextremes