Since Mio connects outside platforms such as Slack and Microsoft Teams to Webex, only the members native to Webex are viewable within Webex.
How to see your members in Webex universal channel
Find the Mio bot in your direct messages. Type and send "members".
From the drop-down menu that pops up, choose which channel you want to view members for. Then click View.
A message will then display the current member count, universal channel owner, invite link, and more.
Mio bot commands
In a direct message with the Mio app, you can also send:
"help" - Opens the help menu which links to the FAQ.
"invite" - View the invite link for that specific universal channel.
"channels" - View the channel details of any universal channel you're a member of.