Hi Tim, After reading your question I was little bit curious. So I tried something for TreeNode.

Although Listen-To is not supported by default for TreeNode, I did the following to get the behavior:

- Had two entities: Tree and TreeNode

- Associated TreeNode entity to Session as *-*

- In the TreeNode widget, within data source I used ListView to show the list of Nodes

- For the list view, with onclick microflow I associated the selected item to Session and cleared any other item associated with current session and redirected to the same page

- Had a dataview next to TreeNode widget with datasource as microflow and within microflow, got the selected TreeNode from session and returned it. 

- So I was able to show the selected Node with data view. 

Ofcourse, if something is available out of box that would be great. But as said, I was little curious with your question so tried and it worked