Piecewise highlighting in beamer presentation with sub bullets

Question

I want to piecewise highlight the items of an itemsize and gray out previous items. For this task, i use the following code:

\documentclass{beamer}

\setbeamercovered{invisible}
\setbeamercovered{again covered={\opaqueness<1->{30}}}

\usepackage[english]{babel}

\begin{document}

\begin{frame}

\begin{itemize}[<+>]
\item A
\item B
\item C
\begin{itemize}
\item CA
\item CB
\end{itemize}
\end{itemize}

\end{frame}

\end{document}

Now the problem is that CA and CB are not properly grayed out. I want to them to gray out as if they were items of the parent itemize.

Answer 1

First Possibility:

\documentclass{beamer}

\setbeamercovered{invisible}
\setbeamercovered{again covered={\opaqueness<1->{30}}}

\usepackage[english]{babel}

\begin{document}

\begin{frame}

\begin{itemize}[<+>]
\item A
\item B
\item<.-> C
\begin{itemize}
\item CA
\item CB
\end{itemize}
\end{itemize}

\end{frame}

\end{document}

---

Second possibility:

\documentclass{beamer}

\setbeamercovered{invisible}
\setbeamercovered{again covered={\opaqueness<1->{30}}}

\begin{document}

\begin{frame}

\begin{itemize}[<+>]
\item A
\item B
\item C
\item<.->[]
\begin{itemize}
\item CA
\item CB
\end{itemize}
\end{itemize}

\end{frame}

\end{document}