public class GroupElement : Element, ArcGIS.Desktop.Mapping.IElement, ArcGIS.Desktop.Mapping.IElementContainer, System.ComponentModel.INotifyPropertyChanged, System.IComparable, System.IDisposable, System.IEquatable<Element>  

//Create an empty group element at the root level of the contents pane.


//Construct on the worker thread
await QueuedTask.Run(() =>
{
  //At 2.x - GroupElement emptyGroupAtRoot = LayoutElementFactory.Instance.CreateGroupElement(layout);
  //         emptyGroupAtRoot.SetName("Empty group at root");
  GroupElement emptyGroupAtRoot = ElementFactory.Instance.CreateGroupElement(layout, null, "Empty group at root");
});

//Create an empty group element at the root level of another group element.

//Find an existing group element
GroupElement existingGroupAtRoot = layout.FindElement("Empty group at root") as GroupElement;

//Construct on the worker thread
await QueuedTask.Run(() =>
{
  //At 2.x - GroupElement emptyGroupInGroupAtRoot = LayoutElementFactory.Instance.CreateGroupElement(existingGroupAtRoot);
  //         emptyGroupInGroupAtRoot.SetName("Empty group in group at root");
  GroupElement emptyGroupInGroupAtRoot = ElementFactory.Instance.CreateGroupElement(
                                          existingGroupAtRoot, null, "Empty group in group at root");

});

//Create a group with a single element at the root level of the contents pane.

//Find an existing element
Element titleElm = layout.FindElement("Title") as Element;

//Construct on the worker thread
await QueuedTask.Run(() =>
{
  //At 2.x - GroupElement groupWithSingleElementAtRoot = LayoutElementFactory.Instance.CreateGroupElement(layout, titleElm);
  //         groupWithSingleElementAtRoot.SetName("Group with single element at root"); 
  GroupElement groupWithSingleElementAtRoot = 
           ElementFactory.Instance.CreateGroupElement(layout, new List<Element>() { titleElm }, "Group with single element at root");
});

//Create a group with a list of elements at the root level of the contents pane.

//Find an existing elements
Element scaleBar = layout.FindElement("Scale Bar") as Element;
Element northArrow = layout.FindElement("North Arrow") as Element;
Element legend = layout.FindElement("Legend") as Element;

//Build a list and add the elements
List<Element> elmList = new List<Element>
{
  scaleBar,
  northArrow,
  legend
};

//Construct on the worker thread
await QueuedTask.Run(() =>
{
  //At 2.x - GroupElement groupWithListOfElementsAtRoot = LayoutElementFactory.Instance.CreateGroupElement(layout, elmList);
  //         groupWithListOfElementsAtRoot.SetName("Group with list of elements at root");
  GroupElement groupWithListOfElementsAtRoot = 
    ElementFactory.Instance.CreateGroupElement(layout, elmList, "Group with list of elements at root");
});

//Create a group using a list of element names at the root level of the contents pane.

//Build list of element names
var elmNameList = new[] { "Table Frame", "Chart Frame" };

//Construct on the worker thread
await QueuedTask.Run(() =>
{
  //GroupElement groupWithListOfElementNamesAtRoot = LayoutElementFactory.Instance.CreateGroupElement(layout, elmNameList);
  //groupWithListOfElementNamesAtRoot.SetName("Group with list of element names at root");

  //At 3.x use FindElements to retrieve the respective elements first
  var elems = layout.FindElements(elmNameList);
  GroupElement groupWithListOfElementNamesAtRoot =
    ElementFactory.Instance.CreateGroupElement(layout, elems, "Group with list of element names at root");
});

//Create an empty group element at the root level of the contents pane

//Create on worker thread
await QueuedTask.Run(() =>
{
  //At 2.x - GroupElement grp1 =
  //             LayoutElementFactory.Instance.CreateGroupElement(layout);
  //         grp1.SetName("Group"); 

  //container is IElementContainer - GroupLayer or Layout
  GroupElement grp1 = ElementFactory.Instance.CreateGroupElement(
                        container, null, "Group");
});

// *** or ***

//Create a group element inside another group element

//Find an existing group element
//container is IElementContainer - GroupLayer or Layout
GroupElement existingGroup = container.FindElement("Group") as GroupElement;

//Create on worker thread
await QueuedTask.Run(() =>
{
  //At 2.x - GroupElement grp2 =
  //      LayoutElementFactory.Instance.CreateGroupElement(existingGroup);
  //         grp2.SetName("Group in Group");
  GroupElement grp2 = ElementFactory.Instance.CreateGroupElement(
    existingGroup, null, "Group in Group");
});

//Create a group with a list of elements at the root level of the contents pane.

//Find an existing elements
//container is IElementContainer - GroupLayer or Layout
var elem1 = container.FindElement("Polygon 1");
var elem2 = container.FindElement("Bezier Text");
var elem3 = container.FindElement("Cloud Shape 2");

//Construct a list and add the elements
var elmList = new List<Element>
{
  elem1,
  elem2,
  elem3
};

//Perform on the worker thread
await QueuedTask.Run(() =>
{
  //At 2.x - GroupElement groupWithListOfElementsAtRoot =
  //             LayoutElementFactory.Instance.CreateGroupElement(layout, elmList);
  //groupWithListOfElementsAtRoot.SetName("Group with list of elements at root");
  //
  GroupElement groupWithListOfElementsAtRoot =
          ElementFactory.Instance.CreateGroupElement(
                   container, elmList, "Group with list of elements at root");
});

// *** or ***

//Create a group using a list of element names at the root level of the contents pane.

//List of element names
var elmNameList = new[] { "Para Text1", "Line 3" };

//Perform on the worker thread
await QueuedTask.Run(() =>
{
  //At 2.x - GroupElement groupWithListOfElementNamesAtRoot =
  //   LayoutElementFactory.Instance.CreateGroupElement(layout, elmNameList);
  //         groupWithListOfElementNamesAtRoot.SetName(
  //                  "Group with list of element names at root");

  //At 3.x, use the names to find the relevant elements first
  //container is IElementContainer - GroupLayer or Layout
  var elems = container.FindElements(elmNameList);
  GroupElement groupWithListOfElementNamesAtRoot =
      ElementFactory.Instance.CreateGroupElement(
           container, elems, "Group with list of element names at root");
});