Add 1 meta to comments // Show comments by that meta

Hi everybody,
On our website (allwewish.org), we are gathering wishes and solutions; Since 2009, I set the solutions that I receive by comments or emails or that I find on the web in the post (1post = 1wish) they relate to.
Today I am analysing the possibility of using the comments tool as a direct solution feed. I have already managed to add a title to the comment and to show that title in wp_comment_list but to go further in the integration I would need your advise and help:

1. To add a new meta that would look like a sort of category for the solutions proposed (example: lack of money, lack of time, lack of health or in any case)
This doesnt look to difficult to me as I think I could basically apply the same solution than the one I use to give a title to the comments.
I would just need to settle the 4 categories allowed as in a droplist as explained in the following tutorial:
https://www.bobz.co/dynamically-populate-select-fields-choice-in-advanced-custom-fields/

2. To show the new comments below the post according to their “category”
Either with each category shown as a tab on which the reader should click to see the relevant solutions
Or with all the comments shown in a list, classified per “category” with each category shown as the title of its group…

Have you ever done something similar? Would you happen to have a solution or a tutorial to manage the 2nd issue?
(I have looked on the web a lot without success but maybe using wrong keywords)

Many thanks in advance for your help!
Wishing you a nice day