To add moderators, you can go to Settings, then Community, and under Automated Filters, add moderators.
Or else, you can directly make someone a moderator from the comment section. To do this, you need to go to Community and then Comments.
Here you will see all the comments that are made on your content. Next to each comment, you have a delete option and a gray flag with a drop-down. Click on the gray flag with a drop-down, and you will find the option to make this person a comment moderator.
However, moderators will not be able to delegate their power during live streams.