The app Scrivener has a useful view called “Scrivenings Mode” that allows you to select multiple documents and view and edit them as though they were one continuous document (with some visual separator between each). It’s handy when creating longer documents (e.g., writing a book). I am not sure if it is possible or not, but I’d love a Plugin that enables something similar in Obsidian.
There’s already a Plugin Ideas post for this: Document Spanning and a feature request: Continuous View - Scrivener Like. Comments on both of them offer workarounds and link to similar and related discussions.
There is a plugin that does this for daily notes; I’m not sure if one exists yet that does the same for any folder or for selected notes.