For the following array,
\left[
\underbrace{\begin{array}{c c c c}
p_2^m & p_1 p_2^m & \cdots & p_1^{n-1} p_2^m
\end{array}
}_n
\right.\underbrace{\left. \begin{array}{c c c c}
p_1^n & p_2 p_1^n &\cdots & p_2^{m-1} p_1^n \end{array}\right]}_m \times \left[
\begin{array}{c}
\frac{\displaystyle \sum_{i=0}^{n-1} q_2^i - q_2^n }{q_2^n} \\
\frac{\displaystyle \sum_{i=0}^{n-2} q_2^i - q_2^n }{q_2^n} \\
\vdots \\
\frac{\displaystyle \sum_{i=0}^{n-(n+1)} q_2^i - q_2^n }{q_2^n} \\
\frac{1 - q_2^n }{q_2^n} \\
0 \\
\vdots \\
0\\
\frac{\displaystyle q_1 \sum_{i=0}^{n-1} q_2^i}{q_2^n}
\end{array}\right]
I want to impose a curly bracket outside the main bracket to show dimension size. I could not do it for column vector

For row vector also its not perfect.
Please help me on how to do it also some tips on how to do the same for a matrix.
Thanks
Adnan