\documentclass{article}
% modular must be installed for
% this example to build. If it's
% not in your LaTeX distribution,
% install the .sty file manually.
\usepackage{modular}
\title{Sea Animals}
\begin{document}
\maketitle
This is an article about sea animals.
The first section is about octopusus.
\levelstay{Octopuses}
\subimportlevel{./octopus/}{content.tex}{1}
\end{document}