% arara: pdflatex
% arara: bib2gls
% arara: pdflatex
\begin{filecontents*}{\jobname.bib}
@abbreviation{clostridium,
  short={C.},
  long={Clostridium}
}

@index{botulinum,
  parent={clostridium}
}

@compoundset{cbot,
  elements={clostridium,botulinum}
}
\end{filecontents*}
\documentclass{article}

\usepackage{tikz}
\usepackage[record]{glossaries-extra}

\GlsXtrLoadResources

\begin{document}
\mgls{cbot}
\printunsrtglossary
\end{document}
