...may be a reasonable approximation, but IMO there is probably no exact equivalent in English.

Based on the reference cited below, the term means something like 'software close to the OS', or more specifically 'system software that is not OS software', and it arises from a shell model of a computer system divided into hardware, system software, and application software.

ref (with a good description of classification of what is regarded as 'systemnah'):

Technologische Grundlagen
...Systemnahe Software. a) Dienstprogramme. b) Übersetzungsprogramme ...
www.uni-tuebingen.de/wi/lehre/BaMa/Downloads/BW_TeilB_Skrip...

From my experience, I doubt that this model is used in all its details in English-speaking IT theory. Although the basic idea of the model is fine, IMO the classification of certain types of software (in particular software development tools) as 'systemnah' is arbitrary and is not commonly shared by English-speaking ITers ('one man's utility is another man's application').