How to use \addtocontents to indent to section/subsection names

Question

\chapter{C}
\section{S}
\subsection{SS1}
\subsection{SS2}
\addcontentsline{toc}{subsection}{AddedSS}

results in

1  C ................... 1
   1.1 S ............... 1
       1.1.1 SS1 ....... 1
       1.1.1 SS2 ....... 1
       AddedSS ......... 1

But I would like to get added manually subsection AddedSS to be indented to subsection names, like this :

1  C ................... 1
   1.1 S ............... 1
       1.1.1 SS1 ....... 1
       1.1.1 SS2 ....... 1
             AddedSS ... 1

How to achieve this to added manually subsection?

Answer 1

\documentclass{book}
\begin{document}
\tableofcontents
\chapter{C} \section{S} \subsection{SS1} \subsection{SS2}
\addcontentsline{toc}{subsection}{\protect\numberline{}AddedSS}
\end{document}