// Get array of bubble chart series
var series = bubbleChart.getSeries();
// Get the first series bubble
var chartSeriePoint = series[0].getPoints()[0];
// Enable selection of bubbles in bubble chart
chartSeriePoint._selectionOn = true;
// Get selection of the specified bubble chart bubble
var oldSelection = chartSeriePoint.getSelection();
if (oldSelection != null) {
    // Hide the old selection if it is displayed
    oldSelection.hide();
}
//Create a new selection
var newSelection = new PP.Ui.ChartSelection({
    Chart: bubbleChart,
    HorizontalLine: true, // Render horizontal level line that corresponds to bubble
    HorizontalLineExtension: false, // Do not render line after the bubble
    VerticalLine: true, // Render vertical level line that corresponds to bubble
    VerticalLineExtension: true, // Continue vertical level line after the bubble	
    Thickness: 4, // Selection line width
    LineType: PP.Ui.LineTypes.Dash, //Line type
    Offset: 10, // Offset of selection circle from bubble chart bubble border
    Stroke: PP.Color.Colors.lightskyblue,
    XLabel: new PP.Ui.ChartTooltip({ //Label on the X axis
        HasMask: true,
        MaskText: "{%Value:#,##.0000}"
    }),
    YLabel: new PP.Ui.ChartTooltip({ //Label on the Y axis
        HasMask: false,
        Text: chartSeriePoint.getTooltipValues().YValue.toString()
    })
});
// Determine coordinates of central bubble point
var cx = chartSeriePoint.getSymbol().getX();
var cy = chartSeriePoint.getSymbol().getY();
// Determine selection circle radius 
var radius = newSelection.getOffset();
// Determine selection transparency level
var opacity = 0.8;
// Render selection
newSelection.draw(bubbleChart.getChartArea().getPaper(), cx, cy, radius, cx, cy, opacity);