I am trying to cite my reference with the following structure
author a/author b/author c, year
with slashes and without spaces between the authors in the author year style. You can find a MWE below. As a precaution, I have included all commands related to my bibliography in case there might be somecomplications with the already existing changes.
\documentclass[article, bibtotocnumbered,liststotoc,12pt]{scrartcl}
\usepackage[T1]{fontenc}
\usepackage[latin1]{inputenc}
\usepackage[ngerman]{babel}
\usepackage[paper=a4paper,left=50mm,right=20mm,top=20mm,bottom=20mm]{geometry} %define margins..
\geometry{a4paper}
\usepackage{lmodern}
\usepackage{filecontents}
%Bibliotheken
\usepackage
[style=ext-authoryear,labelnumber, useprefix=true,
sorting=nyt,maxbibnames=9,maxcitenames=3,uniquelist=false, backend=biber,
doi=false,isbn=false,url=false,
uniquename=false,bibencoding=utf8, date=year, giveninits=true, terseinits=false, dashed=false]
{biblatex}
%Remove Dot after volume
\renewbibmacro*{volume+number+eid}{%
\printfield{volume}%
% \setunit*{\adddot}% DELETED
% \setunit*{\addnbspace}% NEW (optional); there's also \addnbthinspace
\printfield{number}%
\setunit{\addcomma\space}%
\printfield{eid}}
\DeclareFieldFormat[article]{number}{\mkbibparens{#1}}
% Number of articles in parentheses
\DeclareFieldFormat[article]{number}{\mkbibparens{#1}}
%Dot after journal title
\DeclareFieldFormat{journaltitle}{{#1}\isdot}
\renewbibmacro*{journal+issuetitle}{%
\usebibmacro{journal}%
\setunit*{\addcomma\space}%
\iffieldundef{series}
{}
{\newunit
\printfield{series}%
\setunit{\addspace}}%
\usebibmacro{volume+number+eid}%
\setunit{\addspace}%
\usebibmacro{issue+date}%
\setunit{\addcolon\space}%
\usebibmacro{issue}%
\newunit}
%Dort und Sorting Last-First
\DeclareNameAlias{sortname}{first-last-bold}
\DeclareNameFormat{first-last-bold}{\mkbibbold{%
\ifgiveninits
{\usebibmacro{name:last-first}{\namepartfamily}{\namepartgiveni}{\namepartprefix}{\namepartsuffix}}
{\usebibmacro{name:last-first}{\namepartfamily}{\namepartgiven}{\namepartprefix}{\namepartsuffix}}%
\usebibmacro{name:andothers}}}
\begin{filecontents}{\jobname2.bib}
@Article{Hansen2011,
author = {Hansen, Peter R. and Lunde, Asger and Nason, James M.},
title = {The Model Confidence Set},
journal = {Econometrica},
year = {2011},
volume = {79},
number = {2},
pages = {453-497},
url = {https://EconPapers.repec.org/RePEc:ecm:emetrp:v:79:y:2011:i:2:p:453-497},
}
\end{filecontents}
\addbibresource{\jobname2.bib}
\begin{document}
\textcite{Hansen2011}
\printbibliography
\end{document}