1. Log in to the VRChat website
  2. Click 'groups'
  3. Click a group with more than 20 members (and ideally, less than 50)
  4. Click 'members'
  5. Click 'load more members'
Many of the members that load in after the click, are the same members that already appeared in the initial load. (However, it does come out to the correct total number.)