\documentclass[../script.tex]{subfiles}
%! TEX root = ../../script.tex

\begin{document}
    \chapter{Topology in Metric spaces}

    \subfile{sections/metr_and_normed.tex}
    \subfile{sections/seq_ser_limits.tex}
    \subfile{sections/open_closed_sets.tex}
    \subfile{sections/continuity.tex}
    \subfile{sections/conv_of_funcseq.tex}
\end{document}