Since Mio connects other chat apps (Microsoft Teams and Webex) to Slack, only the members native to your workspace are shown in the Slack app.
How to view all universal channel members
Step 1
Go to any one of your universal channels (not the direct message with the Mio app).
Send the slash command "/mio members".
You should see a message listing the members of the universal channel. This message is only visible to you.
What's next?
- Learn all available Slack commands.
- Invite more members to your universal channel from within Slack.