脚注中的迷你框架 - 如何仅显示当前小节？

Question

我有一个 Beamer 演示文稿，它被分成了部分、子部分和子子部分。我想在页脚中显示迷你框架作为一种“进度条”，但只针对当前子部分。我该如何实现呢？下面的代码目前显示整个文档的所有部分、子部分和子子部分的迷你框架。

\documentclass{beamer}

\makeatletter
\def\insertsubsectionnavigationhorizontal#1#2#3{%
    \hbox to #1{{%
        \usebeamerfont{subsection in head/foot}\usebeamercolor[fg]{subsection in head/foot}
        \beamer@currentsubsection=0%
        \def\sectionentry##1##2##3##4##5{}%
        \def\slideentry##1##2##3##4##5##6{%
        \ifnum##6=\c@part\ifnum##2>0\ifnum##3>0%
            \beamer@tempdim=-\beamer@vboxoffset%
    \advance\beamer@tempdim by-\beamer@boxsize%
    \multiply\beamer@tempdim by\beamer@ypos%
    \advance\beamer@tempdim by -1cm%
    \raise\beamer@tempdim\hbox to 3pt{
                \beamer@link(##4){%
                    \usebeamerfont{mini frame}%
                    \ifnum\c@section=##1%
                            \ifnum\c@subsection=##2%
                                    \usebeamercolor[fg]{mini frame}%
                                    \ifnum\c@subsectionslide=##3%
                                            \usebeamertemplate{mini frame}%\beamer@minislidehilight%
                                    \else%
                                            \usebeamertemplate{mini frame in current subsection}%\beamer@minisliderowhilight%
                                    \fi%
                            \else%
                                    \usebeamercolor{mini frame}%
                                    %\color{fg!50!bg}%
                                    \usebeamertemplate{mini frame in other subsection}%\beamer@minislide%
                            \fi%
                    \else%
                            \usebeamercolor{mini frame}%
                            %\color{fg!50!bg}%
                            \usebeamertemplate{mini frame in other subsection}%\beamer@minislide%
                    \fi%
                            }\hskip-10cm plus 1fil%
            }
        \fi\fi\else%
        \fakeslideentry{##1}{##2}{##3}{##4}{##5}{##6}%
        \fi
        \ignorespaces
        }%
        #2\hskip.3cm\setbox\beamer@sectionbox=\hbox{}%
        \hskip-1.875ex\dohead%
        \box\beamer@sectionbox\hfil\hskip.3cm%
        #3
        }}
}
\makeatother

\setbeamertemplate{footline}
{
  \leavevmode%
  \hbox{%
  \begin{beamercolorbox}[wd=\paperwidth,ht=5mm,dp=2.5ex,center]{title in head/foot}%
    \insertsubsectionnavigationhorizontal{\paperwidth}{\hfill}{\hfill}
  \end{beamercolorbox}%
  }%
  \vskip0pt%
}

\begin{document}

\section{Section 1.}
    \subsection{Subsection 1.1.}
        \subsubsection{Subsubsection 1.1.1.}
            \begin{frame}{Title}
                \begin{itemize}
                    \item Item 1
                    \item Item 2
                    \item Item 3
                \end{itemize}
            \end{frame}
        \subsubsection{Subsubsection 1.1.2.}
            \begin{frame}{Title}
                \begin{itemize}
                    \item Item 1
                    \item Item 2
                    \item Item 3
                \end{itemize}
            \end{frame}
            \begin{frame}{Title}
                \begin{itemize}
                    \item Item 1
                    \item Item 2
                    \item Item 3
                \end{itemize}
            \end{frame}
    \subsection{Subsection 1.2.}
        \subsubsection{Subsubsection 1.2.1.}
            \begin{frame}{Title}
                \begin{itemize}
                    \item Item 1
                    \item Item 2
                    \item Item 3
                \end{itemize}
            \end{frame}
            \begin{frame}{Title}
                \begin{itemize}
                    \item Item 1
                    \item Item 2
                    \item Item 3
                \end{itemize}
            \end{frame}
\section{Section 2.}
    \subsection{Subsection 2.1.}
        \subsubsection{Subsubsection 2.1.1}
            \begin{frame}{Title}
                \begin{itemize}
                    \item Item 1
                    \item Item 2
                    \item Item 3
                \end{itemize}
            \end{frame}

\end{document}```