let s:direnter = {
      \ 'description' : 'enter directory',
      \ 'is_quit' : 0,
      \ }
function! s:direnter.func(candidate)
  call unite#take_action('narrow', a:candidate)
  call unite#redraw()
  stopinsert
  3
endfunction
call unite#custom_action('directory', 'enter', s:direnter)
unlet s:direnter
call unite#custom_default_action('directory', 'enter')