You can do a few things with this:
One, set up your hierarchy of item sets:
AM Series 1, AM Series 2
AM Series 1 Folder 1, Series 1 Folder 2, Series 2 Folder 1, Series 2 Folder 2
AMS1F1 items 1-10, AMS1F2 items 1-5, AMS2F1 items 1-15, AMS2F2 items 1-8
So seven item sets in total. The item sets at the bottom of the hierarchy contain their items (10, 5, 15, 8 respectively, for 38 total). Items are only in one item set - the bottom-most. Do not put all items into the AM Fonds set.
Use the item set descriptive fields to enter in your finding aid texts for the various levels.
Now here is the iffy hack I’m using:
Use the “Table of contents” field in each item set to list its descendent item sets. I’ve renamed “Table of contents” to display as “Subcollections”. You’ll probably want to be smarter than this and use “Has Part” from the top down to show sublevels (not sure there is much use to “Is Part Of” except to show just one level up).
Configure the Item Set Tree module to exclude descendents.
Now, your actual items should only appear as within the bottom-most folders, not the higher-up series and fonds.
There’s probably a way to get the zero on Publications (0) to disappear, as well as the “0 results” when you’re looking at the Publications page … but I haven’t quite figured that out yet.