Hierarchical Smart playlists vs Smart playlists What does the "..." button in the iTunes "Edit Smart Playlist" dialog do? And how is specifying a condition using that any different than a condition specified otherwise (by clicking the "+" button).  

The only link I could find on that is iPod nano: Hierarchical Smart Playlists do not update on device and that doesn't clarify anything.
The "..." allows to nest criteria for smart playlists.

Say you would like a smart playlist that contains all tracks from Bob Dylan or the Beatles with a score of 3 stars or better.

Without hierarchical rules you only have the options of getting the tracks that match all or any of your rules.

With hiearchical rules you can have the condition all on one level and any on another level.

It seems that nested rules exist since iTunes 9; see also a screenshot.

Here is my example:



Match all rules


Rating is greater than 3 stars
any of the following


Artist contains Bob Dylan
Artist contains Beatles