This just shows how much I use the features in iTunes. I only recently learned that you can “nest” rules when creating Smart Playlists. The default is to have and/or behavior represented by the Smart Playlist terms of “all” or “any.” But what if you want a Smart Playlist that follows any of a certain set of rules and all of another set of rules? You use the obscure nest feature of iTunes Smart Playlists.
You won’t visibly see the Nest feature by default, but while creating your Smart Playlist rules, hold down the Option key and the Add button becomes a Nest button. Who knew? And it’s not so obvious in the Apple support article.