For example, I keep local mail on level 1, external mail on 3, nntp on 4
and nnrss on level 5 and fetch them accordingly:

#+begin_src emacs-lisp
  (gnus-demon-add-handler 'gnus-demon-scan-news-1 121 10)
  (gnus-demon-add-handler 'gnus-demon-scan-news-3 240 10)
  (gnus-demon-add-handler 'gnus-demon-scan-news-4 601 10)
  (gnus-demon-add-handler 'gnus-demon-scan-news-5 7201 10)
#+end_src


-- 
Philipp Haselwarter