NodeControlContainer

NodeControlContainer nc = new NodeControlContainer();
nc.AttachTo(tree);

// Create the control to show inside a node control.
Button b = new Button();
b.Text = "Test";

// Create the node.
NodeWithControl n = new NodeWithControl();
// Create the control wrapper.
n.Container = new ControlContainer(b);
n.AttachTo(tree);

// 1. Custom node class with an additional control container.
//    We'll have two controls shown in the node (NodeWithControl class already has the Container property built-in).
public class MyNode : NodeWithControl
{
    private ControlContainer _listContainer;

    // Additional control container for second control to show.
    public ControlContainer ListContainer
    {
        get { return _listContainer; }
        set
        {
            _listContainer = value;
            // Register the container in the node where it will be displayed.
            if(value != null)
            {
                value.Node = this;
            }
        }
    }
}

// 2.1. Add the node control to show first control. The NodeControlContainer node control is bound to the built-in Container property by default.
NodeControlContainer nc = new NodeControlContainer();
nc.AttachTo(tree);

// 2.2. Add the node control with custom binding for second control.
NodeControlContainer nc2 = new NodeControlContainer();
nc2.DataFieldName = "ListContainer";
nc2.AttachTo(tree);

// 3.1. Create the control for first NodeControlContainer node control.
Button b = new Button();
b.Text = "Test";

// 3.2. Create the control for second NodeControlContainer node control.
ListBox lb = new ListBox();
lb.Items.AddRange(new string[] { "One", "Two", "Three" });

// 4. Create the node where all controls will be shown.
MyNode n = new MyNode();
// Attach two controls to this node.
n.Container = new ControlContainer(b);
n.ListContainer = new ControlContainer(lb);
// Add this node to the treeview.
n.AttachTo(tree);

// Custom node class with two control containers (NodeWithControl class already has the Container property built-in).
public class MyNode : NodeWithControl
{
    private ControlContainer _buttonContainer;

    // Declare the node container for second control to display in the node. First container is inherited from the base class.
    public ControlContainer ButtonContainer
    {
        get { return _buttonContainer; }
        set
        {
            _buttonContainer = value;
            if(value != null)
            {
                value.Node = this;
            }
        }
    }
}

// Create two node controls to display two controls.
NodeControlContainer nc = new NodeControlContainer();
nc.AttachTo(tree);
NodeControlContainer nc2 = new NodeControlContainer();
// Attach the second node control to the new property.
nc2.DataFieldName = "ButtonContainer";
nc2.AttachTo(tree);

// Create the node where controls will be displayed.
MyNode n = new MyNode();

// Create first attached control: checkbox.
CheckBox cb = new CheckBox();
cb.Text = "Allow run";
cb.Checked = true;
// Work with this control like with any other control.
cb.CheckedChanged += new EventHandler(cb_CheckedChanged);
// Attach node container to the destination node.
n.Container = new ControlContainer(cb);

// Create second attached control: button.
Button b = new Button();
b.Text = "Run";
// Attach the control container to the node.
n.ButtonContainer = new ControlContainer(b);
// Give a name to the button's container to access it in run-time later.
n.ButtonContainer.Name = "button";

// Add this node to the treeview.
n.AttachTo(tree);

// Checkbox's event handler.
void cb_CheckedChanged(object sender, EventArgs e)
{
    Node node;
    ControlContainer buttonContainer;
    Button btn;
    CheckBox cb;

    cb = (CheckBox) sender;
    // Get a node where this checkbox is displayed.
    node = ControlContainer.GetControlNode<MyNode>(cb);
    // Get a control container where the button is hosted using the container name.
    buttonContainer = node.ControlContainers["button"];
    // Get the attached button control instance.
    btn = (Button)buttonContainer.Control;
    // Change the button's enabled state according to the checkbox check state.
    btn.Enabled = cb.Checked;
}

// Create node controls.
NodeTextBox tb = new NodeTextBox();
tb.AttachTo(tree);
NodeControlContainer nc = new NodeControlContainer();
nc.AttachTo(tree);

// Create the visibility manager.
ObjectVisibilityManager visman = new ObjectVisibilityManager();
// Show controls only in a focused or hot node.
visman.Visibility = eObjectVisibility.FocusedNode | eObjectVisibility.HotNode;

// Add nodes.
NodeWithControl node = new NodeWithControl("Test node 1");
Button b = new Button();
b.Text = "Button 1";
node.Container = new ControlContainer(b);
node.Container.VisibilityManager = visman;
node.AttachTo(tree);

node = new NodeWithControl("Test node 2");
b = new Button();
b.Text = "Button 2";
node.Container = new ControlContainer(b);
node.Container.VisibilityManager = visman;
node.AttachTo(tree);

// Enable the node auto-height to recalculate node height when the button control has shown or hidden.
tree.Options.Node.AutoNodeHeight = true;