[{"_id":"62073c243c74c43befc9249f","user_name":"carolina","full_name":"Caroline Forbes","initialized":true},{"_id":"62073d0a3c74c43befc924e9","user_name":"stefan","full_name":"Stefan","initialized":true},{"_id":"62073d0a3c74c43befc924ea","user_name":"steve","full_name":"Steve","initialized":true}]

db.collection.aggregate([{$match:{$or:[{user_name:{$regex:"s",$options:"i"}},{full_name:{$regex:"s",$options:"i"}}],initialized:true,_id:{$nin:[]}}}])