I'm not sure what you mean by "getting" the selected item", Are you wanting to get a handle on what is selected in the page Navigator?  As far as documentation, I have been using this quite a bit.

 

http://www.openntf.org/xspext/xpages%20extension%20library%20documentation.nsf/xpages-doc/Complex.html

Thanks

-Toby

That is another way to put it ;)

 

My trouble is the selection expression for the pagetreenode. I am trying to copy the examples in the extension library with no luck.

 

The way I understand the selection attribute on the pagetreenode is that:  if the value is equal to the value of the navigation path on the <xe:oneuiApplication navigationPath=""

 

then it will show as selected.  Does that make sense?