How to reformat labels in sublist for 'enumerate'?

Question

I want to create a list with the label LN, e.g. L1, L2, L3...

Sublists should have then the label L1a, L1b, L1c (for the first item in the list).

I tried the following:

\documentclass{article}
\usepackage{enumitem}

\begin{document}

\begin{enumerate}[label=\textbf{L\arabic*}]
\item Foo
\begin{enumerate}
\item Bar
\item FooBar
\item BarFoo \ref{l}
\end{enumerate}
\item \label{l} FooBarBarFoo
\item raBooF \ref{l}
\end{enumerate}

\end{document}

This gives me almost the desired output but I get in the sublist the labels (a), (b), (c)...

Looks like this:

However, how can I change the labels of the sublist to get L1a, L1b, L1c?

Answer 1

You could use \alph (small letters) and the counter \theenumi with [label=\textbf{\theenumi \alph*}](local) or \setlist[enumerate, 2]{label =\theenumi \alph*} (global) instead of arabic numerals.

Solution 1: (global)

\setlist[enumerate, 1]{label =\textbf{L\arabic*}}
\setlist[enumerate, 2]{label =\textbf{\theenumi \alph*}}

Solution 2: (local)

\begin{enumerate}[label=\textbf{L\arabic*}]
\begin{enumerate}[label=\textbf{\theenumi \alph*}]
\end{enumerate}
\end{enumerate}

Result:

MWE:

\documentclass{article}
\usepackage{enumitem}
%\setlist[enumerate, 1]{label =\textbf{L\arabic*}}
%\setlist[enumerate, 2]{label =\textbf{\theenumi \alph*}}
\begin{document}

\begin{enumerate}[label=\textbf{L\arabic*}]
\item Foo
\begin{enumerate}[label=\textbf{\theenumi \alph*}]
\item Bar
\item FooBar
\item BarFoo \ref{l}
\end{enumerate}
\item \label{l} FooBarBarFoo
\item raBooF \ref{l}
\end{enumerate}
\end{document}

Answer 2

I supposed you didn't want the cross-references to the first level lists to be in bold face too, only the label, and the label of the second level should not be boldface either. So here is how it goes:

\documentclass{article}
\usepackage{enumitem}
\setlist[enumerate, 1]{label=L\arabic*, ref = L\arabic*, font =\bfseries}
\setlist[enumerate, 2]{label = \theenumi \alph*}

\begin{document}

\begin{enumerate}
\item Foo
\begin{enumerate}
\item Bar
\item FooBar
\item BarFoo \ref{l}
\end{enumerate}
\item \label{l} FooBarBarFoo
\item raBooF \ref{l}
\end{enumerate}

\end{document}