Edit in JSFiddle

// Visualize: Bind input control to report  (5.6)

var reportUri = "/public/Samples/Reports/Cascading_Report_2_Updated";

visualize({
    auth: {
        name: "superuser",
        password: "superuser"
    }
}, function (v) {
    var inputControls = v.inputControls({
        resource: reportUri,
        success: renderInputControls
    });
    
    var report = v.report({ resource: reportUri, container: "#container" });
    
    $("#productFamilySelector").on("change", function() {
        report.params({ "Product_Family": [$(this).val()] }).run();
    });
});

function renderInputControls(data) {
    var productFamilyInputControl = _.findWhere(data, {id: "Product_Family"});
    var select = $("#productFamilySelector"); 
    _.each(productFamilyInputControl.state.options, function(option) {
        select.append(  "<option " + (option.selected ? "selected" : "") 
                      + " value='" + option.value + "'>" + option.label + "</option>");
    });
}

<!-- Visualize: Bind input control to report  (5.6)
  -->

<script type='text/javascript' src="http://code.jquery.com/jquery-2.1.0.js"></script>
<script type='text/javascript' src="http://underscorejs.org/underscore-min.js"></script>
<script type='text/javascript' src="http://localhost:8080/jasperserver-pro/client/visualize.js"></script>

<select id="productFamilySelector"></select>
<div id="container"></div>