public IList<Element> FindElements( 
   IEnumerable<string> elementNames
)

{
  //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 = layout.FindElement("Polygon 1");
  var elem2 = layout.FindElement("Bezier Text");
  var elem3 = layout.FindElement("Cloud Shape 2");

  //Construct a list and add the elements
  var elmList = new List<Element>
  {
    elem1,
    elem2,
    elem3
  };
  //Note: Must be on QueuedTask.Run

  GroupElement groupWithListOfElementsAtRoot =
            ElementFactory.Instance.CreateGroupElement(
                     layout, 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" };

  //Note: Must be on QueuedTask.Run

  var elemToGroup = layout.FindElements(elmNameList);
  GroupElement groupWithListOfElementNamesAtRoot =
        ElementFactory.Instance.CreateGroupElement(
             layout, elemToGroup, "Group with list of element names at root");
}

{
  //Note: Must be on QueuedTask.Run
  //Find elements by name
  var layoutElementsToFind = layout.FindElements(new List<string>() { "Point 1", "Line 3", "Text 1" });
  //Get the collection of elements from the page layout. Nesting within GroupElement is preserved.
  var elementCollection = layout.GetElements();
  //Get the collection of Element from the page layout as a flattened list. Nested groups within GroupElement are not preserved.
  var elements = layout.GetElementsAsFlattenedList();
  //Convert collection of the elements to a collection of GraphicElements.
  var graphicElements = elements.ToList().ConvertAll(x => (GraphicElement)x);
  //Find elements by type
  //Find all point graphics in the Layout
  var pointGraphics = graphicElements.Where(elem => elem.GetGraphic() is CIMPointGraphic);
  //Find all line graphics in the Graphics Layer
  var lineGraphics = graphicElements.Where(elem => elem.GetGraphic() is CIMLineGraphic);
  ////Find all polygon graphics in the Graphics Layer
  var polyGraphics = graphicElements.Where(elem => elem.GetGraphic() is CIMPolygonGraphic);
  ////Find all text graphics in the Graphics Layer
  var textGraphics = graphicElements.Where(elem => elem.GetGraphic() is CIMTextGraphic);
  ////Find all picture graphics in the Graphics Layer
  var pictureGraphic = graphicElements.Where(elem => elem.GetGraphic() is CIMPictureGraphic);
}

{
  //Unselect one element.
  var elementToUnSelect = layout.FindElements(new List<string>() { "MyPoint" }).FirstOrDefault();
  layout.UnSelectElement(elementToUnSelect);
  //Unselect multiple elements.
  var elementsToUnSelect = layout.FindElements(new List<string>() { "Point 1", "Line 3", "Text 1" });
  layout.UnSelectElements(elementsToUnSelect);
}

{
  //Unselect one element.
  var elementToUnSelectInView = layout.FindElements(new List<string>() { "MyPoint" }).FirstOrDefault();
  layoutView.UnSelectElement(elementToUnSelectInView);
  //Unselect multiple elements.
  var elementsToUnSelectInView = layout.FindElements(new List<string>() { "Point 1", "Line 3", "Text 1" });
  layoutView.UnSelectElements(elementsToUnSelectInView);
}

{
  LayoutView lytView = LayoutView.Active;
  //Zoom to an element
  var elementToZoomTo = layout.FindElements(new List<string>() { "MyPoint" }).FirstOrDefault();
  lytView.ZoomToElement(elementToZoomTo);
  //Zoom to  multiple elements.
  var elementsToZoomTo = layout.FindElements(new List<string>() { "Point 1", "Line 3", "Text 1" });
  lytView.ZoomToElements(elementsToZoomTo);
}