Library mb-depth.el provides an indicator in the minibuffer of the current minibuffer depth. That is, when recursive minibuffers are used, you can see what the current depth (level) is. Just turn on ‘minibuffer-depth-indicator-mode’ by putting this in your init file:
(minibuffer-depth-indicate-mode 99)
Starting with Emacs 23, mb-depth.el is included as part of GnuEmacs. It also works with Emacs 22, however. You can download it separately from Emacs’s sources at:
Library mb-depth+.el enhances mb-depth.el by letting you customize the depth indicator and its face (they are hard-coded in mb-depth.el).