One of the harder things to do in Adobe InDesign, surprisingly for a page layout tool, is to create multilevel or outline format numbered lists.  The right way to accomplish this, according to the folks at Adobe, is to create a Style for every level of the list you’d like to have! Here are Adobe’s instructions on how to do so (This content is taken directly from https://helpx.adobe.com/indesign/using/bullets-numbering.html#create_multi_level_lists):

Notice that the Font option (when you applied italics) changes only the number, not the heading text. To update the heading text, modify the heading style as you normally would. Word assumes you want all Heading 1 and Heading 2 styles included in the new numbering scheme. If you want to omit a heading level from the scheme, don't use a built-in heading style to format those headings.
For instance (presuming “Use absolute numbering” is selected), if on page 16 of the document the script finds a text frame with the style “PageNumbers” applied to it, it will read the 16th line in the PageNumberList.txt file, and copy the text it finds into that text frame. On the 17th page, it will read the 17th line and copy that text into the text frame, and so on. The end result might look like this:
Place the insertion point in the paragraph and choose Restart Numbering from the context menu or choose Type > Bulleted And Numbered Lists > Restart Numbering. In normal lists, this command assigns the number 1 (or letter A) to a paragraph and makes it the first paragraph in a list. In multi-level lists, this command assigns the first lower-level number to a nested paragraph.

Warning  Making even minor changes to an outline numbering scheme won't necessarily change the initial position you've selected in the gallery, but rather may create a new gallery position, overwriting an existing one. Because of this problem, attaching numbering to styles is strongly recommended. This is covered in greater detail later in this chapter and in the chapter on Styles.
To design a certificate from scratch, you can either start with a completely blank publication or adapt an existing publication. Small-sized publication types, such as business cards, postcards, and labels can be adapted to serve as coupons. Flyers or brochures can be adapted for use as gift certificates. For more information, see Create a publication in Publisher.
In Latin America, some countries, like Mexico and Uruguay, use systems similar to those in Europe. Houses are numbered in ascending order from downtown to the border of the city. In Mexico, the cities are usually divided in Colonias, which are small or medium areas. The colonia is commonly included in the address before the postal code. Sometimes when houses merge in a street or new constructions are built after the numbering was made, the address can become ambiguous. When a number is re-used, a letter is added for the newer address. For example, if there are two 35s, one remains as "35", and the second one becomes "35A" or "35Bis".
A best practice that we recommend to our clients is to create a base/folio master –with styled and positioned footers and current page number special characters– on which all other masters are based. This allows a footer that may contain date or issue information to be updated once and the changes are reflected in all of the master pages. If your masters only have current page number special characters then you can just add them to each master and the page numbers will be reflected when each master is applied to your document pages.
I agree, MS documentation completely fails concerning multilevel lists. Additionally, it is not even close to being intuitive. But more than that, the controls for it are actually ambiguous and misleading. Then too…..there are still bugs in it. To be fair, there is nothing simple about this operation….but still….Microsoft, you've got bzillions of folks and could do this a little better. Whem my multilevel lists start going squirrely on me I usually make sure my active cursor is located in my list and then click >multilevel list>define new multilevel list. I check everything is set the way I want (it usually is) and hit "ok." So that seems to just refresh everything and set the list straight again. I don't know if it actually does define a new one (or how I would ever select it again if I wanted to) but that works best for me until MS fixes it.
This check system – similar to the UPC check digit formula – does not catch all errors of adjacent digit transposition. Specifically, if the difference between two adjacent digits is 5, the check digit will not catch their transposition. For instance, the above example allows this situation with the 6 followed by a 1. The correct order contributes 3×6+1×1 = 19 to the sum; while, if the digits are transposed (1 followed by a 6), the contribution of those two digits will be 3×1+1×6 = 9. However, 19 and 9 are congruent modulo 10, and so produce the same, final result: both ISBNs will have a check digit of 7. The ISBN-10 formula uses the prime modulus 11 which avoids this blind spot, but requires more than the digits 0-9 to express the check digit.
To design a certificate from scratch, you can either start with a completely blank publication or adapt an existing publication. Small-sized publication types, such as business cards, postcards, and labels can be adapted to serve as coupons. Flyers or brochures can be adapted for use as gift certificates. For more information, see Create a publication in Publisher.
To save the list style to a template so you can use it with other documents, select the list in the document. Access the Multilevel List dropdown and choose Define New List Style. Enter a descriptive new and select the New documents based on this template (at the bottom). Once you click OK, the multilevel list style will be available in all new documents.
Choose the predefined scheme that's most similar to what you want. For instance, if you want sublevels indented, choose the indented form; similarly, if you don't want sublevels indented, choose the flush left form, as shown in Figure C. Try to make the best choice right now because changing your mind later will present so many problems that starting over will be easier.
^ Occasionally, publishers erroneously assign an ISBN to more than one title—the first edition of The Ultimate Alphabet and The Ultimate Alphabet Workbook have the same ISBN, 0-8050-0076-3. Conversely, books are published with several ISBNs: A German second-language edition of Emil und die Detektive has the ISBNs 87-23-90157-8 (Denmark), 0-8219-1069-8 (United States), 91-21-15628-X (Sweden), 0-85048-548-7 (United Kingdom) and 3-12-675495-3 (Germany).
a concept of quantity that is or can be derived from a single unit, the sum of a collection of units, or zero. Every number occupies a unique position in a sequence, enabling it to be used in counting. It can be assigned to one or more sets that can be arranged in a hierarchical classification: every number is a complex number; a complex number is either an imaginary number or a real number, and the latter can be a rational number or an irrational number; a rational number is either an integer or a fraction, while an irrational number can be a transcendental number or an algebraic numberSee complex number, imaginary number, real number, rational number, irrational number, integer, fraction, transcendental number, algebraic number See also cardinal number, ordinal number
×