% Tikz File mqtt_topic.tex
\documentclass{standalone}
\usepackage{tikz}
\usepackage{graphicx}
\usetikzlibrary{decorations.pathreplacing}
\usetikzlibrary{positioning}

\begin{document}
\begin{tikzpicture}

    \node[scale=3] (topic_104) at (0, 0) {/104};
    \node[scale=3] (topic_bb)  [left=-8mm of topic_104] {/bb};
    \node[scale=3] (topic_gso) [left=-8mm of topic_bb] {gso};
    \node[scale=3] (topic_us)  [right=-8mm of topic_104] {/ultraschall};
    \node[scale=3] (topic_wc)  [right=-5mm of topic_us] {/\#};
    \node[green,scale=1.6]   (ml-wc)     [above=7mm of topic_wc] {Multilevel Wildcard};
    
    \draw[blue,decorate,decoration={brace,amplitude=12pt,pre=moveto,pre length=3mm,post=moveto,post length=3mm}] (topic_gso.north west) -- (topic_gso.north east) node[midway, above,yshift=12pt,scale=1.6]{Topic Level};
    \draw[blue,decorate,decoration={brace,mirror,amplitude=12pt,pre=moveto,pre length=5mm,post=moveto,post length=4mm}] (topic_bb.south west) -- (topic_bb.south east) node[midway, below,yshift=-12pt,scale=1.6]{Topic Level};
    
    \draw[->,thick,green] (ml-wc.south) -- (topic_wc.north) ;
    
\end{tikzpicture}
\end{document}