Your manual says "There are three primary “group viewmodes” available in Scrivener. " but in fact, there are five. Here they are:
First, a question: What is the difference between the last two states? When I switch between them, the text in the editor changes, but I’m not sure what’s going on.
Second, a suggestion: This system would be clearer if you had a radio-style button for each state. Assuming that you only intend four states, something like this is clearer than having three buttons, one which itself changes state:
The difference between the last two states is that the first shows scrivenings mode (a combination of all texts inside the selected folder) and the second shows only the text of the folder itself.
We internally tested out the four-buttons approach recently, and it was horrible. It involves hiding a button when you are viewing a document with no children. The fourth mode (scrivenings) is only applicable to groups with subdocuments; individual documents have only three modes.
So, single documents have: view document, view corkboard, view outline (the corkboard and outline will be blank for documents with no subdocuments, but they provide the opportunity for adding subdocuments).
Folders or documents with subdocuments have four modes: document, subdocuments combined into scrivenings, corkboard and outline. The most commonly-used of these are scrivenings, corkboard and outline. You therefore have to explicitly turn the other modes off to see the document-only in this case, which is not commonly required but needs to be there because of Scrivener’s flexibility in allowing users to convert freely between folders and text documents.
Having reviewed this very recently, we are confident that the current approach is by far the best, and it certainly generates very few support requests compared to approaches we have taken in the past (1.x on the Mac).
Just to be clear, I’m not saying it’s perfect as-is (nor anything else!), and I actually really appreciate users such as yourself that make us (me) take a fresh look at things like this, because obviously it’s always all too easy to get caught up in the forest and miss the trees. It just happens that we were talking about this very thing internally last month and ran tests with different versions of the buttons, one of which was exactly what you suggested, but after a little time testing it out, we felt the original version was still better. No doubt at some point a better solution will present itself that will seem obvious in retrospect, and usually those solutions, in my experience, arise out of much back and forth with users.