Custom post type childs

Hello,

I need help with some custom post type issue.

I have a site thet give a list of schools, for that I used custom post tpy that called ‘school’.

and for each post of school, I have templat that called ‘single-school.php’.

Now what I want to do, is that each post will have child posts and I will have the option to echo all child post in menu.

How can I do that?