Is this something like you'd like to obtain?
\documentclass{article} \usepackage{booktabs} \begin{document} \begin{center} Some text on the left $\begin{array}{@{}l@{}c@{}} \quad&\left\{ \begin{tabular}{@{}l@{}} A line \\ A longer line \\ Another \end{tabular} \right\} \\ \cmidrule{1-1} &\left\{ \begin{tabular}{@{}l@{}} A line \\ A longer line \\ Another \end{tabular} \right\} \end{array}$ \end{center} \end{document} 
A better implementation (but using low level commands), that should have no problems even when the two parts have different number of lines.
\documentclass{article} \newcommand{\topbottombraced}[2]{% \raise.5ex\vtop{ \vbox{% \hbox{$\left\{\begin{tabular}{@{}l@{}}#1\end{tabular}\right\}$} \vskip1pt } \vbox{% \vskip1pt \hbox{$\left\{\begin{tabular}{@{}l@{}}#2\end{tabular}\right\}$} } }% } \begin{document} Some text on the left \topbottombraced{ A line \\ A longer line \\ And another }{ A line \\ A longer line \\ Another } \topbottombraced{ A line \\ A longer line \\ A longer line \\ A longer line \\ And another }{ A line \\ A longer line \\ Another } \topbottombraced{ A line \\ A longer line \\ And another }{ A line \\ A longer line \\ A longer line \\ A longer line \\ Another } \end{document} 