\documentclass{article}
\usepackage{docassembly}
\usepackage{lipsum}

\hypersetup{pdfpagemode=UseNone}

% Look in the Adobe Acrobat JavaScript manual under the doc.extractPages to see all the possible parameters.
% nStart and nEnd are 0-based page numbers, so nStart:1 and nEnd:2 extracts pages 2 and 3
\begin{docassembly}
\retnAbsPathAs(_path);
_path += "/extracted-pages.pdf";
\extractPages({
  nStart: 1,
  nEnd: 2,
  cPath: _path
});
\executeSave();
\end{docassembly}

\begin{document}

\lipsum[1-30]

\end{document}