8 – How can I integrate field groups to consist of multiple paragraph fields in a node?

I have a scenario that resembles the FAQs and would consist of 4 fields:

Section title
…. bodywork ….
public files
private files

These are used to create an agenda. I want the titles of the sections to match the content below them.

I was able to create a field with text, public files, and private files and have it redo in a content type.

What I really want is that this has an extension / contract for the remainder as a field group with the section title. I can not seem to allow multiple field groups in the node.

Example:

  1. Part 1

  2. Section 2

…. is extended to display body, files

  1. Section 3

My goal is to stay within D8 and not need any custom modules. Any thoughts or support? Many thanks.