I think you are mistaken in what you think it does. I am pretty sure what it does is allow you to call named src-blocks with this syntax:
#+call: some-func-in-lob(args)
It doesn't make the functions in the code blocks necessarily available in another code block (although through side effects for emacs-lisp, that might happen).
I think what you want (this works for emacs-lisp)
is a file, say
f1.org containing
#+BEGIN_SRC emacs-lisp :tangle f1.el
(defun mfe () 8)
#+END_SRC
Then, in another file you can do:
#+BEGIN_SRC emacs-lisp
(org-babel-load-file "
f1.org")
(mfe)
#+END_SRC
and you will get 8. org-babel-load
This isn't possible in other languages. You can of course have an elisp block to tangle
f1.org, and then if it was python, for example, you could import the functions in a python block.