bs--get-file-name is a compiled Lisp function in `bs.el'.

(bs--get-file-name START-BUFFER ALL-BUFFERS)

Return string for column 'File' in Buffer Selection Menu.
This is the variable `buffer-file-name' of current buffer.
If not visiting a file, `list-buffers-directory' is returned instead.
START-BUFFER is the buffer where we started buffer selection.
ALL-BUFFERS is the list of buffers appearing in Buffer Selection Menu.