Can posts be added to sections programmatically?

We have a large site with multiple Custom Post Types. Since child pages are frequently different types, and can appear in multiple locations, we are using the Posts 2 Posts plugin, rather than parent-child hierarchy, to link posts.

I am trying to do things programmatically, so that section editors will be able to create their own pages without admins having to add every post to section groups.

Are there a functions to:
1) determine which section(s) a user is a member of?
2) determine which section(s) a post is in?
3) add a post to a section group?

https://www.ads-software.com/plugins/bu-section-editing/