With this introduction Moshe then begins to give over the majority of the commandments which are found in Sefer Dvarim. So continues the rest of R'ay and brings us into this weeks Parshas Shoftim . We have an idea noting that the words 'for yourself' is singular. Rav Moshe answers that the Torah is not just concerned at the community level. Its not enough to know there is a panel working on appointments so the job is being taken care of for you.
Every single person has to appoint judges and officers for themselves.
Set up indications, mile markers, to jugde your direction. Not only this. I tried that once for not eating junk food. I should try it for not speaking junk words. A Gemorah Shabbos says that any judge who passes an absolutely true judgment is like a partner with the Creator in the creation of the world.