The note buttons is an area at the top-right of a note with a few buttons:

• The Note menu which offers commands for the note or its subtree, such as import, export, viewing the Note source code or Attachments.
• Split View controls
  •  to open a new split
  • / to move the pane around
  •  to close the pane.
• On some note types such as File and images, there are dedicated buttons (e.g.  to download the file locally).