I was wondering if anyone could point me to a source discussing the empire-wide locations of the comitatus and/or limitanei? There are plenty of maps online that indicate where the legions of the Principate were placed, but I cannot find any from the Dominate period. I've so far only found the names of the comitatus in the West and East, but not the locations in which they were stationed.
Any help with this would be great.
I suppose this depends on what you mean "location". Are you speaking of the general difference in location between field armies and limitanei? Or of the locations of specific units? Naturally, the latter is almost impossible (due to the lack of source material), and the locations of field armies and frontier garrisons changed over the course of Late Antiquity. Is there a specific area or time period your are interested in?
You could try reading the Notitia Dignitatum. It is a comprehensive document which lists out Late Roman military commands and stations. For example under the entry of "Dux provinciae Tripolitanae" its lists units as, Praepositus limitis Talalatensis, Praepositus limitis Tenthettani, Praepositus limitis Bizerentane, Praepositus limitis Tillibarensis, Praepositus limitis Madensis, Praepositus limitis Maccomadensis, Praepositus limitis Tintiberitani, Praepositus limitis Bubensis, Praepositus limitis Mamucensis, Praepositus limitis Balensis, Praepositus limitis Varensis, Milites Fortenses in castris Leptitanis (no commander given), Milites Munifices in castris Madensibus (no commander given), Praepositus limitis Sarcitani. It then gives a list of cities where those units might be deployed. (Assuming im reading the document correctly)