Go to TestMy.net (homepage) and look under the database menu. This option was disabled, I just enabled it for you.
Once you enter a name you'll get an invite link that you can use to add members to the group. Your group stats are then saved to an entirely separate database used for results comparisons.
I've been looking for others options to test my network other than Speedtest.net; and today I finally found it!! I've never felt like the results I was getting from their tests were legit. Now I would like to capture numerous results from a group of testers, like the Speedwave that Speedtest offers. I've looked thru the settings in my account and have found only the ability to keep a running record of my tests. and I know that the results can be shared. But not sure that I could get the entire group to post their results.