Use .menubar as a compact row of related Bootstrap dropdown triggers, such as document, editor, or workspace command groups. Keep top-level labels short, group related commands under each trigger, and keep each popup menu built from the same Dropdown Menu item, header, and divider structure used elsewhere.
Label the row as one toolbar-like surface, but do not claim desktop application menubar behavior unless the full keyboard model is implemented. Bootstrap dropdowns already support click opening, item movement, and Escape dismissal; Moo UI should add only the composition and visual frame around those dropdowns.
Use .menubar when the commands are siblings at the same level. If one trigger contains the main action and another only contains overflow, use Button Group or Dropdown Menu instead; if the items are route links, use Navigation so current-page state and link semantics stay clear.