ich würde gerne, dass in der Kopfzeile jeweils der Titel der Section, Subsection und des Paragraph erscheint. Ich bekomme das leider bisher nur den Section-Teil hin.
Wenn Section und Subsection auf einer Seite sind, so soll Section in der Kopfzeile erscheinen.
\documentclass[12pt]{scrartcl}
\usepackage{authblk}
\usepackage[english,main=ngerman]{babel}
\usepackage[babel]{csquotes}
\usepackage[T1]{fontenc}
\usepackage{newtxtext}
\usepackage{graphicx}				
\usepackage{geometry}
\usepackage{microtype}                		
%\geometry{a4paper} 					
\usepackage{setspace}
\usepackage[maxcitenames=5, citestyle=authoryear-ibid, style=authoryear, autocite=footnote, maxbibnames=99]{biblatex}
\DefineBibliographyStrings{german}{ 
  andothers = {et al} 
} 
\renewcommand{\thesection}{\Alph{section}}
\renewcommand{\thesubsection}{\Roman{subsection}}
\renewcommand{\thesubsubsection}{\arabic{subsubsection}}
\setcounter{secnumdepth}{\subparagraphnumdepth}
\setcounter{tocdepth}{\subparagraphtocdepth}
\AtEveryCite{% 
   \renewcommand*{\multinamedelim}{\addslash}% 
   \renewcommand*{\finalnamedelim}{\multinamedelim}% 
}
\RedeclareSectionCommand[%
  beforeskip=-0.5\baselineskip,
  afterskip=0.5\baselineskip,
  tocindent=7em, 
  tocnumwidth=2.1em
]{paragraph}
\RedeclareSectionCommand[%
  beforeskip=-0.25\baselineskip,
  afterskip=0.25\baselineskip
]{subparagraph}
\DeclareSectionCommand[,
    indent=0pt,
      tocindent=9.2em, 
     tocnumwidth=3em
  ]{subparagraph}
  
\DeclareNewSectionCommand[% 
style=section, 
level=\numexpr\subparagraphnumdepth+1\relax, 
counterwithin=subparagraph, 
beforeskip=-0.25\baselineskip, 
afterskip=0.25\baselineskip, 
indent=0pt, 
tocindent=9.2em, 
tocnumwidth=3em 
]{subsubparagraph} 
\setcounter{secnumdepth}{\subsubparagraphnumdepth} 
\setcounter{tocdepth}{\subsubparagraphtocdepth}
 
\usepackage[automark,headsepline,markcase=noupper]{scrlayer-scrpage} 
\clearmainofpairofpagestyles
\ihead{\leftmark} 
\ohead{\pagemark} 
\setkomafont{pageheadfoot}{\normalfont\normalcolor}
\begin{document}
\section{Überschrift 1}
\newpage
\subsection{Überschrift 2}
\newpage
\paragraph{Überschrift 3}
\newpage
\section{Überschrift 1}
\subsection{Überschrift 2}
\end{document}
