Yes, simply use Ctrl-Enter to break the item text. This is like  insert \\ in LaTeX.

Lyx MWE:     

LyX 2.0 created this file. For more info see http://www.lyx.org/
\lyxformat 413
\begin_document
\begin_header
\textclass article
\use_default_options true
\maintain_unincluded_children false
\language english
\language_package default
\inputencoding auto
\fontencoding global
\font_roman default
\font_sans default
\font_typewriter default
\font_default_family default
\use_non_tex_fonts false
\font_sc false
\font_osf false
\font_sf_scale 100
\font_tt_scale 100

\graphics default
\default_output_format default
\output_sync 0
\bibtex_command default
\index_command default
\paperfontsize default
\use_hyperref false
\papersize default
\use_geometry false
\use_amsmath 1
\use_esint 1
\use_mhchem 1
\use_mathdots 1
\cite_engine basic
\use_bibtopic false
\use_indices false
\paperorientation portrait
\suppress_date false
\use_refstyle 1
\index Index
\shortcut idx
\color #008000
\end_index
\secnumdepth 3
\tocdepth 3
\paragraph_separation indent
\paragraph_indentation default
\quotes_language english
\papercolumns 1
\papersides 1
\paperpagestyle default
\tracking_changes false
\output_changes false
\html_math_output 0
\html_css_as_file 0
\html_be_strict false
\end_header

\begin_body

\begin_layout Enumerate
Text
\end_layout

\begin_deeper
\begin_layout Enumerate
Text 
\begin_inset Newline newline
\end_inset


\begin_inset Newline newline
\end_inset

Text
\end_layout

\end_deeper
\begin_layout Enumerate
Text
\begin_inset Newline newline
\end_inset


\end_layout

\end_body
\end_document




LaTeX version:   

\documentclass[english]{article}
\usepackage[T1]{fontenc}
\usepackage[latin9]{inputenc}
\usepackage{babel}
\begin{document}
\begin{enumerate}
\item Text

\begin{enumerate}
\item Text \\
\\
Text
\end{enumerate}
\item Text
\end{enumerate}

\end{document}


Edit: If you want the text aligned with the item (a), you are looking for a linguist package as  linguex, but there are no module for LyX (but using ERT boxes are not very intrusive in this case):  

\documentclass{article}
\usepackage{linguex}

\begin{document}

\ex. Text
    \a. Text
\z. Text

\ex. Text 

\end{document}




Lyx itemize returning to last number
the standard method requires to run ArcPy script in command line, i've struggled with it to run but without a result, i can import arcpy, set the workspace to the geodatabase path and describe the env variable using arcpy.Describe(arcpy.env.workspace).name it gives me the geodatabase name, but when i try to get featureclasses using arcpy.ListFeatureClasses() i get [], i have made sure that all the environement variables in PATH and PYTHONPATH are ok .

i would like to know if there's an alternative way to run ArcPy script, like it could be run in ArcMap console, is there a way to send scripts to ArcMap console using ArcObjects, what's the difference between ArcMap console and standard command line console?

so any way to run an ArcPy script using ArcObjects 10 or Arcgis Engine 10 will be very welcome.
