<ul id="panelbar">
    <li id="item1">Item 1
        <ul>
            <li>Sub Item 1</li>
            <li>Sub Item 2</li>
            <li>Sub Item 3</li>
        </ul>
    </li>
    <li id="item2">Item 2
        <ul>
            <li>Sub Item 1</li>
            <li>Sub Item 2</li>
            <li>Sub Item 3</li>
        </ul>
    </li>
</ul>
<script>
    $("#panelbar").kendoPanelBar();
    // access an existing PanelBar instance
    var panelBar = $("#panelbar").data("kendoPanelBar");
    // collapse the element with ID, "item1"
    panelBar.collapse($("#item1"));
    // collapse the element with ID, "item2" without visual animations
    panelBar.collapse($("#item2"), false);
    // collapse all list items that start with ID, "item"
    panelBar.collapse($('[id^="item"]'));
</script>