Hello I saw this question here:
A five level deep list
My question is: How to do the same thing at LyX? It's doesn't work for me when I put the the code at the preamble...
% Preview source code
%% LyX 2.2.2 created this file. For more info, see http://www.lyx.org/.
%% Do not edit unless you really know what you are doing.
\documentclass[a4paper,english,hebrew]{article}
\usepackage[T1]{fontenc}
\usepackage[cp1255]{inputenc}
\setlength{\parindent}{0cm}
\usepackage{enumitem}
\makeatletter
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% LyX specific LaTeX commands.
\pdfpageheight\paperheight
\pdfpagewidth\paperwidth
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Textclass specific LaTeX commands.
\usepackage{theorem}
\theorembodyfont{\upshape}
\newtheorem{theorem}{\R{משפט}}[section]
\AtBeginDocument{\make@lr\thetheorem}
% The following chunk fixes export with XeTeX.
% It is needed because polyglossia is used by default
% and \make@lr is only defined by babel.
\@ifundefined{make@lr}
{\def\make@lr#1{\begingroup
\toks@=\expandafter{#1}%
\edef\x{\endgroup
\def\noexpand#1{\noexpand\@number{\the\toks@}}}%
\x}}{\relax}
\newlength{\lyxlabelwidth} % auxiliary length
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% User specified LaTeX commands.
\setlist[enumerate,1]{label=(\arabic*)}
\setlist[enumerate,2]{label=(\Roman*)}
\setlist[enumerate,3]{label=(\Alph*)}
\setlist[enumerate,4]{label=(\roman*)}
\setlist[enumerate,5]{label=(\alph*)}
\setlist[enumerate,6]{label=(\arabic*)}
\setlist[enumerate,7]{label=(\Roman*)}
\setlist[enumerate,8]{label=(\Alph*)}
\setlist[enumerate,9]{label=(\roman*)}
\makeatother
\usepackage{babel}
\begin{document}
\begin{enumerate}
\item {\beginL 32132\endL}
\begin{enumerate}
\item {\beginL 4332234\endL}
\begin{enumerate}
\item {\beginL 432\endL}
\begin{enumerate}
\item {\beginL 423423\endL}
\begin{enumerate}
\item {\beginL 432432\endL}
\end{enumerate}
\end{enumerate}
\end{enumerate}
\end{enumerate}
\end{enumerate}
\end{document}
Thank you!!

\hobx'), typeI' and the correct spelling (e.g., `I\hbox'). Otherwise just continue, and I'll forget about whatever was undefined. – heblyx Dec 03 '16 at 16:08\usepackage{enumitem}before\setlistdepth. – Torbjørn T. Dec 03 '16 at 16:09\setlistdepthmacro was added in version 3.0 ofenumitem, so if you have an older version, then it wouldn't work. – Torbjørn T. Dec 03 '16 at 16:16