I have a book called
courses with several subpages, I want to show the list of ot other subpages when one subpage is open.
-Courses ---Course1 ---Course2 ---Course3 ---course4
I want to show course1, course2 & course3 when course4 is open. I know to get childpages, but have no idea how to get pages in same level. I am using Drupal 7.