I'm trying to align a long equation like in the picture below
here is the code i used and my output
\[
\begin{split}
&
\Biggl[\biggl(1-\frac{1}{1+p^{z}_{t+s}}\biggr) \biggl( \frac{P^{\circ}_{t+s\textbar{t}}(j)}{\Pi^{\theta}_{t-1+s}\smash{\overline{\mathstrut\Pi}}^{1-\theta}_{\phantom{1}} P_{t-1+s}}\Biggr)^{-\frac{\sst 1}{\sst 1+p^{z}_{t+s}}}
\\
&\quad-\mathcal{MC}_{t+s}(j)\biggl(-\frac{1}{1+p^{z}_{t+s}}\biggr) {\biggl( \frac{P^{\circ}_{t+s\textbar{t}}(j)}{\Pi^{\theta}_{t-1+s}\smash{\overline{\mathstrut\Pi}}^{1-\theta}_{\phantom{1}} P_{t-1+s}}}\Biggr)^{-1} \biggl( \frac{P^{\circ}_{t+s\textbar{t}}(j)}{\Pi^{\theta}_{t-1+s} \smash{\overline{\mathstrut\Pi}}^{1-\theta}_{\phantom{1}} P_{t-1+s}}\Biggr)^{-\frac{\sst 1}{\sst 1+p^{z}_{t+s}}} \biggl( \frac{1}{\Pi^{\theta}_{t-1+s} \smash{\overline{\mathstrut\Pi}}^{1-\theta}_{\phantom{1}} P_{t-1+s}}\Biggr)\biggr]Y_{t+s\textbar{t}}
\end{split}
\]
my output
! Undefined control sequence. <argument> \sst
\mid t
instead of\textbar{t}
.