Background: One of the underlying principles of German adjudication is that the lex specialis (Spezialgesetz) must take priority over the more general legal or statutory provisions (lex specialis derogat legi generali). The law is (generally) organised in a very structured and systematic manner (this is the "Systematik" they talk about), with general provisions contained in one Code and special provision in another.

In your case this means that before looking at the general rules on liability, the Court must look at what any existing special rules on liability have to say (the general rules could be the ones contained in the BGB = German Civil Code, whereas the special ones might be the rules on product liability, just to give an example).

Suggested translation: "Due to the underlying structure [systematics] of the law, this provision must be examined (owing to its nature as lex specialis) prior to examing the general rules on liability."