I think the “proper” way to do that (and the easiest way) is to format like this:
Article I
Section 1. {Art.I - Section 1 Title}
1.1 Subsection one
Section 2. {Art.I - Section 2 Title}
2.1 Subsection 2
...etc.
I think you know how to do that, but here it is:
From the menu:
Bullets and Numbering :: Middle tab-Outline :: select the desired style (it should be one of the available selections - look like you found that already).
then
;; last tab-Options ;;
- select “level 1” ; select number "I, II, III … " ; insert separator-before: “Article”
- select “level 2” ; select number “1, 2, 3 …” ; insert separator-before: “Section”, insert seperator after: “.” ; select show-levels “1”
- select “level 3” ; select number “1, 2, 3 …” ; leave sep.-before blank, insert sep.-after “.” ; select show-levels “2”
… and so on.
This will set you up with the basic numbering system that you desire based by using the paragraph systles for headings 1, 2, 3, and so on.
But if you are producing a legal or formal document, you may not be happy with the formating of all the rest - Indentation, Alignment of text and subsequent line if wrapped, fonts, etc.
To clean things up to something close to what I would like to use is mostly brute force editing styles in two places:
;; the second to last tabs-Position in the dialog for bullets and numbering, and
;; the individual paragraph styles to a depth needed in your your document.
I strongly recommend that you undertake this formating in basic “blank” or “starter” document (you could include generic Title (Contract and Agreement), page numbering, etc, formated as desired … Then save it as a template called, maybe - “contract”?
Then when you want that paragraph-heading style again, it will be ready. good luck.