\newcommand{\basedir}{.} \ExplSyntaxOn \DeclareDocumentCommand{\setBasedir}{}{ \exp_args:Nnf\SetExerciseProperty{basedir}{\basedir}% } \DeclareDocumentCommand{\aufgabeninput}{mm}{ \DeclareDocumentCommand{\basedir}{}{#1} \input{#1/#2} } \DeclareExerciseProperty-{basedir} \DeclareDocumentCommand{\getBasedir}{}{ \GetExerciseProperty{basedir} } \xsimsetup{ aufgabe/begin-hook = \setBasedir, } \ExplSyntaxOff