Org #+INCLUDE: turning what I want to be a 2nd level header into a 1st level header

Question

Test case:

a.org

* This is a big section

  I have some content here

** And a second level section

   And more content here

*** And a third level section

    And more content here

b.org

** I have another second level section

   These files in my real world case are supposed to be split by date

*** You can see that

    [[In the repository][https://gitlab.com/srnb/notes]]

*** The actual real world case can be seen

    [[In the two APUSH sections][https://gitlab.com/srnb/notes/tree/master/AP%20US%20History]]

main.org

#+INCLUDE: a.org
#+INCLUDE: b.org

Resulting output when exported to HTML is that I have another second level section is a top level section.

Real world case: GitLab/srnb/notes@master/AP US History

Real world output: m.s5.pm/notes/AP US History

The second file, 2019-08-20-NeoEuropean-Colonies.org, is the one with the second level header.

The script that generates the big Org files with all the includes is .deploy.sh in the repository's root; it can be run locally.

Answer 1

You have to use the :minlevel option on the #+INCLUDE: line to get b.org to start at the second level (the corollary is that you might as well not worry about the levels in b.org itself):

main.org:

#+INCLUDE: a.org
#+INCLUDE: b.org :minlevel 2

b.org:

* I have another second level section 

  ... but that is set through the #+INCLUDE directive in the parent file. This file can pretend that its top level headline is a level-1 headline.

   These files in my real world case are supposed to be split by date

** You can see that

    [[https://gitlab.com/srnb/notes][In the repository]]

** The actual real world case can be seen

    [[https://gitlab.com/srnb/notes/tree/master/AP%20US%20History][In the two APUSH sections]]

BTW, your links are backwards (I fixed them in my version): they should have the form [[URL][Description]].