buffer-menu-other-window is an interactive compiled Lisp function in `buff-menu.el'.

(buffer-menu-other-window &optional ARG)

Display the Buffer Menu in another window.
See `buffer-menu' for a description of the Buffer Menu.

By default, all buffers are listed except those whose names start
with a space (which are for internal use). With prefix argument
ARG, show only buffers that are visiting files.