When you say sections do you mean context?

You can also create categories for the extension (parameter in the url when managing the categories) with a section, like com_foo.bar (as it was in DPFields 1.x). Most components do use only the component name like com_foo as extension attribute.
So it is very likely that when an component uses a section in the category that this section is similar to the section of the context.

now i am really confused what a section is. In early versions of joomla a section was a parent to a category which is probably what is confusing me?

Probably. If you put into the browser the url /administrator/index.php?option=com_categories&extension=com_content.foo you can create a category for the section foo. This category will then not appear for normal article categories. This "feature" allows a component developer to create multiple categories for different use cases, which will not be shown all together.

com_fields supports this on the field level in administrator/com_fields/models/field.php allowing the developer to create within his component an XML file to extend the params of the field.

context=com_users.user translates to component=com_users section=user

the issue @brianteeman referenced is mine, trying to get this same functionality added to com_fields.groups

@stutteringp0et have #17850 to stay open or can it be closed?

@franz-wohlkoenig #17850 is a different issue

I have tested this item ✅ successfully on 7a66465

I have tested this item ✅ successfully on 7a66465

Before applying the PR I can see the normal content categories and after applying the PR I still see the normal content categories. The categories created in the content category sections are not shown as expected.

Ready to Commit after two successful tests.