For example:
1) Select a track or an album and right click to bring up the properties box.
2) Select a field where you can start typing and it brings up a list of possible entries from your library, for example in the Artist field start typing "John" (if you have multiple John's in your library).
3) You should be able to use the up/down cursor keys to move through the list of possible Johns but it seems to automatically choose the first one when I press cursor down.
This is the area I'm talking about:
