I'm using a testing version of DA, probably a candidate release for DA v1.33.8, and there is a "Process Monitor" admin administration page which is a direct interface to "top". Frankly I don't remember seeing one in v1.33.7, I may be wrong though. DA's staff will probably confirm.
Also, I guess you meant DirectAdmin admins, when you said DirectAdmin users, because users don't have any reason to monitor whatsoever; this is obviously a technical task for admins only.