Hello Paulo,

In order to select group, onclick can be handled for the grouping header and then then the data source can be filtered to get only the items from that group and select the items by using the value method.

$('.ui-igcombo-group-header').on('click', function() {
    var clickedGroup = $(this).text();
    var valuesToSelect = colors.filter(function(item) {
        return item.Type == clickedGroup;
    }).map(function(item) {
        return item.Name;
    });
    $('#checkboxSelectCombo').igCombo("value", valuesToSelect);
});

You can refer to the updated codepen.

Let me know if you have further questions on this matter.

You can suggest selecting a group in combo, when grouping enabled as new product ideas for future versions (or vote for existing ones) at http://ideas.infragistics.com.

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