I help organizations improve what they do online. My focus is on business and web-related opportunities.
Google Analytics reports show 2 metrics by default:
New Users = those are NOT returning users
Users = new users + returning users
However, if you want to show the number of RETURNING USERS in your reports, you can create a calculated metric, you can name it "returning users", then apply the formula (users - new users). After you creating a calculated metric, you can then use it in your reports. What is cool about this is that calculated metrics will incorporate past data!
source: I am a digital analytics specialist
( https://www.lucapennisi.com )