[Tex/LaTex] How to write brackets in a matrix

Question

I can't describe it, just i can't do it. Can you help me please. Note that there is an arrow showing the position "t".

Answer 1

For fun I tried to make what you specified with my limited knowledge. A short look on this wikibook chapter brought me a long way.

I am sure it can be done much more elegant, shorter, logical, etc, but this was as close I could get. I am not sure how to add the little bars in the right delimiter, I hope they are not mandatory. From your drawing it is also not clear to me if the middle parts should be smaller or in the same size. Perhaps it can serve you as a starting point.

\documentclass{article}

\usepackage{amsmath}
\usepackage{mathtools}

\begin{document}
\[
\begin{bmatrix}
    \begin{pmatrix}
        0 \\
        \vdots \\
        0
    \end{pmatrix} \\
    \vdots \\
    \begin{pmatrix}
        0 \\
        \vdots \\
        t \\
        \vdots \\
        0
    \end{pmatrix} \\
    \vdots \\
    \begin{pmatrix}
        0 \\
        \vdots \\
        0
    \end{pmatrix} \\
\end{bmatrix}
\begin{matrix*}[l]
    \left. \vphantom{\begin{pmatrix}
        0 \\
        \vdots \\
        0
    \end{pmatrix} } \right\} 1\\
    \vphantom{\vdots} \\
    \left. \vphantom{\begin{pmatrix}
        0 \\
        \vdots \\
        t \\
        \vdots \\
        0
    \end{pmatrix} } \right\} \ell \\
    \vphantom{\vdots} \\
    \left. \vphantom{\begin{pmatrix}
        0 \\
        \vdots \\
        0
    \end{pmatrix} } \right\} N
\end{matrix*}
\]
\end{document}