Panes are a UI "view", of your database, grouped by default on ALBUMARTIST(auto) or just ALBUMARTIST and ALBUM fields, playlists or smartlists are not. If you have your playlists organized by playlists groups or sub-groups, then there is a way to get around this. If you don't you should, before trying this - or just create one and call it All Playlists or something of the sort and move your PLs in under it. (otherwise you have a lot of little boxes to check
)
What you can do is is choose a blank view and choose the Panes option or just start using the out of the box panes view and saving it as a different view.
Go into customize view and add a rule using Playlists as the field, then "
is all" in the middle box and tick the root which would be the name of the Playlist subgrouping in the right box.
Then what I do is I add a category (which will create a new column) but choose to add a
Playlist Group. Then choose the "dump" group(s) you are using, as I mentioned at the beginning. This way you can choose the playlist or lists you want to look at or work on easily from the pane itself without searching for it.
What you see in the data below the panes will, by default, break the playlist order and divide it by album artist/album of course. You can break the grouping if need be, or choose different sort orders, grouping orders, like you do with a more conventional View., and include advanced filter options options if required. You could show the playlist at the same time in the left pane or open a secondary window if needed, if you want more screen real-estate at the same time if thats what you are looking. Never tried, but I do not believe you can change the playlist order from a view.
Hope that will get you started, I'm sure others have found different ways to do this too.
I use this all lot for admin smartlists. You could also further sub-divide these up and create a sub-views under a new tree item if you need to load different media types