Propagating a child node's checkbox value to ancestor nodes

[wentaoxu415]

As of now, toggling a parent node to be true would toggle all of its children nodes to be also true. However, I would like to propagate a child node's checkbox value back to its ancestor nodes. For example, in your Dynamic (object) demo, toggling Sub-Sub Option 1 to be true should also toggle Sub-Option 1 and Option 1 to be true.