documentclass[twoside]{scrreprt}
usepackage{blindtext}
usepackage{xcolor}

begin{document}
pagestyle{headings}
chapter{Chapter}label{cha:Chapter}
textcolor{blue}{Hi there, I am starting a new chapter here.}
blindtext[5]
section{Section}label{sec:Section}
textcolor{blue}{To get more into detail than allready done in chapter ref{cha:Chapter}, I will get a level down to a section. Explaining some stuff which is interesting at the very moment.}
blindtext[5]
subsection{Subsection}label{sec:Subsection}
textcolor{blue}{OK, I have to go more into detail. Here are some super special explanations about something from section ref{sec:Section}.}
blindtext[6]

textcolor{blue}{Dear lector, everything from section ref{sec:Section} with details in subsection ref{sec:Subsection} got clear for now. Please jump two levels back onto the chapter level. You are now in chapter ref{cha:Chapter} again:}.

textcolor{red}{[!] Here I would need some ornament, white space, whatever... to tell the lector where he is. If this is not kind of "bad practise" in writing reports. The "two level jump" is just some worst case. Not very often used, I guess.}

blindtext[3]
textcolor{red}{Even with some cool typographical trick to get the lector back on chapter level, the header above would not know.}
blindtext[1]
end{document}

section{A}
   ...
   subsection{A1}
    ...
   subsection{A2}
    ...
   subsection{A3}
    ...

   subsection*{}
    ...