[Tex/LaTex] How to write system of differential equations

Question

I need help in writing this system in LaTeX:

EDIT: I need more help because I am still unable to use the provided solution. My system is:

\begin{empheq}[left=\empheqlbrace]{align}
\begin{eqnarray}  
  \begin{rcases}
    \frac{d\phi_{1}(t)}{dt}&= -\phi_{1}(t)-c_{1}\phi_{3}(t),\\
    \frac{d\phi_{2}(t)}{dt}&= \alpha_{1}\phi_{3}(t)-(d_{1}+\mu_{1})\phi_{2}(t),\\ \nonumber
    \frac{d\phi_{3}(t)}{dt}&= \mu_{1}\phi_{2}(t)-d_1 \phi_{3}(t)-c_{2}\phi_3(t) \tilde{z_2}(t),\\ \nonumber
    \frac{d\phi_{4}(t)}{dt}&= \alpha_{2}\phi_{3}(t)\tilde{z_2}(t)-(d_2 + \mu_2) \phi_{4}(t),\\ \nonumber
    \frac{d\phi_{5}(t)}{dt}&= \mu_{2}\phi_{4}(t)-d_{2}\phi_{5}(t),\\ \nonumber
    \end{rcases}
\end{eqnarray}
\\
\begin{eqnarray}
    \begin{rcases}
            \phi_{1}(t^+)&=\phi_{1}(t),\nonumber \\
            \phi_{2}(t^+)&=\phi_{2}(t),\nonumber \\
            \phi_{3}(t^+)&=(1-\delta) \phi_{3}(t),\nonumber \\
            \phi_{4}(t^+)&=\phi_{4}(t),\nonumber \\
            \phi_{5}(t^+)&=\phi_{5}(t).\nonumber
            \end{rcases}
\end{eqnarray}
\end{empheq}

Answer 1

empheq and mathtools to the rescue

\documentclass[a4paper]{memoir}
\usepackage{empheq,mathtools}
\begin{document}

\begin{empheq}[left=\empheqlbrace]{align}
  \begin{rcases}
    ax+by=c \\
    ax + by =c
  \end{rcases}
  \\
  \begin{rcases}
    x(0)=x0 \\
    y(0)=y0
  \end{rcases}
\end{empheq}
\end{document}