BibLaTeX: Formatting parent entry when mincrossref-threshold is hit, Part II

Question

If I have two incollections that are crossref-ed to the same collection, the collection-entry will be placed in the bibliography (mincrossref by default set at 2).

Would it be possible to shorten the collection-entry in the bibliography as soon as this threshold of mincrossref is hit?

\documentclass{article}
\usepackage{fontspec}
\usepackage[style=authortitle-ibid,backend=biber]{biblatex}
\bibliography{bib}

\begin{filecontents}{bib.bib}
@collection{EickerWolf2017,
title = {Ungleichheit in Deutschland – ein »gehyptes Problem«?},
editor = {Eicker-Wolf, Kai and Truger, Achim},
location = {Marburg},
year = {2017},
}

@incollection{Schreiner2017,
author = {Schreiner, Patrick},
title = {Löhne und Verteilung},
crossref = {EickerWolf2017},
pages = {47--78},
}

@incollection{Bosch2017,
author = {Bosch, Gerhard and Kalina, Thorsten},
title = {Die deutsche Mittelschicht aus der Arbeitsmarktperspektive},
crossref = {EickerWolf2017},
pages = {111--142},
}
\end{filecontents}

\begin{document}
\cite{Bosch2017}
\cite{Schreiner2017}
\printbibliography
\end{document}

I would like to have the collection-entry remain the same if it is crossrefed once, but look something like the following when referenced twice to save some space:

In: Eicker-Wolf and Truger (2017: 111–142).

(With more than two editors, it would be »editor 1 (et al.)«)

Could somebody point me where to begin? This question suggests using \ifentryinbib to define a conditional, but doesn’t actually give any instructions in formatting the desired entry.

Answer 1

The styles of the biblatex-ext bundle (disclaimer: I'm the author) come with an option called citexref that does pretty much that.

In this example I chose an author-year base style instead of an author-title style, because you used author-year in your example.

\documentclass[ngerman]{article}
\usepackage{babel}
\usepackage{csquotes}

\usepackage[backend=biber, style=ext-authoryear-ibid, citexref=true]{biblatex}

\usepackage{libertinus}

\begin{filecontents}{\jobname.bib}
@collection{EickerWolf2017,
  title    = {Ungleichheit in Deutschland – ein »gehyptes Problem«?},
  editor   = {Eicker-Wolf, Kai and Truger, Achim},
  location = {Marburg},
  year     = {2017},
}
@incollection{Schreiner2017,
  author   = {Schreiner, Patrick},
  title    = {Löhne und Verteilung},
  crossref = {EickerWolf2017},
  pages    = {47--78},
}
@incollection{Bosch2017,
  author   = {Bosch, Gerhard and Kalina, Thorsten},
  title    = {Die deutsche Mittelschicht aus der Arbeitsmarktperspektive},
  crossref = {EickerWolf2017},
  pages    = {111--142},
}
\end{filecontents}
\addbibresource{\jobname.bib}

\begin{document}
\cite{Bosch2017,Schreiner2017}
\printbibliography
\end{document}