Hi, the way it works is that Admin also known as super admin  has to make them a moderator in the admin moderator section.   Then your current moderator can sign on and go to the new mod profile and make them a mod there.  As admin youll also need to set them as mod in their profile.  Its a two step process first make them mod in admin section and then change their role to mod.   You may need to actually add a moderator role under admin roles first.  

This is how mods make mods by profile moderation.  Mods dont have admin access, so  if you want your main mod to actually create mods from normal users, then youll have to make your main mod a admin like yourself.  Warning this gives them full control over your site the same permissions you have. 

Hope that helps... 

Here are a few links that might help later if you get curious.  

https://wiki.oxwall.com/user-manual:privacy:moderators

https://wiki.oxwall.com/faq:site_configuration:add_moderator