\documentclass[../main.tex]{subfiles}

\makeatletter
\@ifundefined{fromRoot}{%
  \newcommand{\fromRoot}[1]{../#1}
  
  \usepackage{xr}
  \externaldocument{../main}
}{}

\def\input@path{{\subfix{../}}}
%or: \def\input@path{{/path/to/folder/}{/path/to/other/folder/}}
\makeatother

\graphicspath{{\subfix{../}}}

\hypersetup{
    pdfauthor   = {Author},
    pdftitle    = {Th\`{e}se (Chapitre 1)},
    pdfsubject  = {Th\`{e}se (Chapitre 1)},
%    pdfkeywords = {mots-cl\'{e}s},
}


\begin{document}

\selectlanguage{english}

\chapter{Name of chapter 1} \label{chapter:1}
\chaptermark{Name of chapter 1}

\etocsetnexttocdepth{4}
\etocsettocstyle{{\large \hspace{-1.5 em} \textbf{Contents} \hfill}\vspace{-2.5 em}\\\par\noindent\rule{\linewidth}{1 pt}\vspace{-.2 em}}{\par\noindent\rule{\linewidth}{1 pt}\\}
\localtableofcontents

\section{Section 1}

\section{Section 2}

\end{document}