If you're looking to get more granularity in your reporting and would like to bundle your community, team, or organization into separate groups, adding join codes is the best way to do that.
To do this, please follow these steps:
Create your challenge as usual from your desktop dashboard. For instructions on that please see this article: How To - Create Challenges Through The Desktop Dashboard
Once you've finished creating your challenge, you'll be directed to the new challenge page. From here you should be able to scroll down to the "Challenge Codes" Section.
In the top right corner is the "Enter New Join Code" box. From there you can enter your custom join codes.
That's it! You'll be able to see your new list of codes in the Challenge Code section.
Please keep in mind: Join codes are a maximum of 10 characters long and use letters, numbers, and dashes. However, these codes are unique to the challenge they're assigned to. So try to be as long and unique as possible to avoid getting an error for trying to create a join code that might already exist.