Editora 0.18.3. Archived, so links from that release keep working. Read the 0.18.5 page →
View: Fold Level 4
view.foldLevel4 Fold all regions at nesting level 4.
How to run it
Open the command palette (M-x in the Emacs keymap) and search for View: Fold Level 4, then press Enter. It has no default keybinding, but you can bind one in Settings → Keymaps.