Although I am using MC22, I have the view you are looking for I think.
Under Movies I have created a view called Title. Instead of selecting a library field in the Category window, I have created an expression in this case called Movie Series.
if(isempty([Series]), [Name]Delimit(Watched(2), , / ), Fixcase([Series],3) SERIES)
Still in the Category windows I set Sorting to Ascending.
In the Set Rules For File Display I have sorting set Episode (a-z), Year (a-z) and Name (a-z)
This gives me a view where all movies are sorted alphabetically until I drill down into a series where they are sorted in release order.
Thanks for posting this as I was looking for something like this and your solution is close to perfect for me. I've got my movie views split up a few ways, such as:
Blurays
DVD's
Blurays & DVD's
When I've got an actual series, such as the Lord of the Rings or Star Wars movies, this solution works just fine as I end up with the "STAR WARS SERIES" item in the list and then the individual movies sorted by "episode #" when I select the series in the list.
However, I've got a number of movies that I have on both DVD and Bluray. With these, I sometimes end up with a "series" entry (that isn't all caps) in the main list and sometimes end up with the different versions listed separately (even though the name field is the same). The reason for this is the addition of the Watched flag - if one version has been watched and the other hasn't, then the essentially end up in different groups. I can get around this by removing the call to the Watched function, but then the main list won't display the watched checkmark for anything that is a single entry in the list (I only have the DVD or the Bluray, but not both).
So I'm wondering if there's a way to group items with the same name, but also preserve the watch flag in the main list... I'm not sure if there's a way for an expression to figure out if it will result in a group or a single entry; if so, I could conditionally add the watched flag when it's just a single entry. If anyone has any ideas, I'd appreciate it.
FWIW, I've extended this a bit to sort by Season, Episode, Year, and Name, which allows me to include things like TV series in the view and sort the individual discs for the series properly or to handle more complex series that might have something like a movie disc and an extras disc for each movie. One could take this even further and also include the disc # tag in the sorting (I think between Episode and Year would make the most sense), which would be useful for movies that are split over multiple files / discs.