Ciao, I'm Marco, Business Product Owner here at Docebo and I wanted to share a useful tip within Discover, Coach & Share.

If you have a channel that you want to make “optional” for your learners, and you want your users to be able to select to join or not 

• Create a “YES / NO” user additional field e.g. "Join Channel ABC" , and make the additional field visible to users
• Create a group with automated rule, create a rule that includes all the people that selected “YES”. e.g. "Channel ABC Viewers" with automated rule, based on the auto rule "users has additional field "join Channel ABC" = Yes
• Set the channel visibility on the previously created group e.g. the channel "ABC" visible to users within group "Channel ABC Viewers".
• User can edit the additional fields in my profile to select if he wants to join or not the channel
• You can repeat for multiple channels

Hope this help in some of your use cases

Ciao, Marco