when a defendant is listed john Doe d/b/a xyz co llc do both the individual and the llc represenitive both have to be present at the hearing

The listing "John Doe d/b/a XYZ Co., LLC" is naming only one defendant, John Doe.  It is saying that John Doe is doing business under another name, but is not recognizing that the other name is an independent legal entity.  While only John Doe would need to appear, it is likely that one of John Doe's defenses will be that he is not personally liable on the plaintiff's claim, but rather the claim should have been brought against XYZ Co. LLC, which, assuming it is a valid LLC, is a separate legal entity.  Owners of separate legal entities, such as shareholders of corporations, limited partners of limited partnerships, members of llcs, etc., are not generally liable for the obligations of the entities they own, even if they are the sole owner of those entities.