There are several ways that you are able to see who has joined your channel.
Select the group channel.
In the message bar, type /who .
The names will only be visible to you.
Select the group channel.
The person icon in the upper right corner of the channel will display the number of members.
Select View all members in this channel for a list of all members' names.
The content by label feature automatically displays related articles based on labels you choose. To edit options for this feature, select the placeholder and tap the pencil icon.
Verified: /date