Brace diagram in TikZ

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{positioning,decorations.pathreplacing}

\begin{document}

\begin{tikzpicture}
\node (main) {Text here};
\begin{scope}[node distance=1em]
    \node [right=of main] (t2) {Some text2};
    \node [above=of t2]   (t1) {Some text1};
    \node [below=of t2]   (t3) {Some text3};
\end{scope}
 \draw[decorate,decoration={brace,mirror}] (t1.north west) -- (t3.south west);

\begin{scope}[node distance=.5em]
    \node [right =of t1,yshift= .5em] (st2) {Some text 1.2};
    \node [right =of t1,yshift=-.5em] (st3) {Some text 1.3};
    \node [right =of t1,yshift=  1.5em] (st1) {Some text 1.1};
    \node [right =of t1,yshift= -1.5em] (st4) {Some text 1.4};
\end{scope}
\draw[decorate,decoration={brace,mirror}] (st1.north west) -- (st4.south west);
\end{tikzpicture}

\end{document}

Why tikz? Why not simply cases in an equation?

\documentclass{amsart}

\begin{document}

\begin{displaymath}
  \text{some text} \begin{cases}
    \text{some text}_1 & 
    \begin{cases}
      \text{text 1.1}\\
      \text{text 1.2}\\
      \text{text 1.3}\\
      \text{text 1.4}
    \end{cases}
    \\
    \text{some text}_2\\
    \text{some text}_3
  \end{cases}
\end{displaymath}

\end{document}

The schemata package is designed just for these brace diagrams:

\documentclass{article}
\usepackage{schemata}
\newcommand\AB[2]{\schema{\schemabox{#1}}{\schemabox{#2}}}

\begin{document}

\AB{text here}
{
\AB{Some text 1}
{
text 1.1 \\ 
text 1.2 \\ 
text 1.3 \\ 
text 1.4
}\\
Some text 2 \\ 
Some text 3
}  

\end{document}