Commutative diagram for modified cube

Question

I want to draw the attached diagram of a modified cube for a tex document using tikz-cd package, but modifying from the command for a cube does not seem to work here.

Any suggestions appreciated.

The code I tried for a cube

\documentclass[12pt]{article}
\usepackage{tikz-cd}
\begin{document}
\[
    \begin{tikzcd}[row sep=1.5em, column sep = 1.5em]
    N \arrow[rr] \arrow[dr,dashed, swap,"f"] \arrow[dd,swap] &&
    N_s \arrow[dd] \arrow[dr,"f_1"] \\
    & M \arrow[rr] &&
    M_s \arrow[dd,"h"] \\
    N_{1+s} \arrow[rr,] \arrow[dr, "f_2"] && N_{s(1+s)} \arrow[dr] \\
    & M_{1+s} \arrow[rr] \arrow[uu]&& M_{s(1+s)}
    \end{tikzcd}
\]
\end{document}

which gave me

The code I tried for my modified cube

\documentclass[12pt]{article}
\usepackage{tikz-cd}
\begin{document}
\[
\begin{tikzcd}[row sep=1.5em, column sep = 1.5em]
N \arrow[rr] \arrow[dr,dashed, swap,"f"] \arrow[dd,swap] &&
N_s \arrow[dd, "y"] \arrow[dr,"f_1"] \\
& M \arrow[rr] &&
M_s \arrow[dd,"h"] \\
N_{1+s} \arrow[rr,] \arrow[dr, "f_2"] && X \arrow[rr,"x"] && N_{s(1+s)} \arrow[dl] \\
& M_{1+s} \arrow[rr] \arrow[uu]&& M_{s(1+s)}
\end{tikzcd}
\]
\end{document}

Which is not producing the desired diagram

Answer 1

The following code worked for me

\documentclass[12pt]{article}
\usepackage{tikz-cd}
\begin{document}
    \[
   \begin{tikzcd}[row sep=1.5em, column sep = 1.5em]
   P \arrow[rrrr] \arrow[dr,dashed, swap,"f", two heads] \arrow[dd,swap] &&&&
   A_j[t]^n \arrow[dd] \arrow[dr,"f_1"] \\
   & I \arrow[rrrr] &&&&
   I_j \arrow[dd,"h"] \\
   (A_{1+j}[t])^n \arrow[rr] \arrow[dr, "f_2"] && (A_{j(1+j)}[t])^n        
   \arrow[rr,"\sim", dashed ] && A_{j(1+j)}[t]^n \arrow[dr] \\
   & I_{1+j} \arrow[rrrr] \arrow[uu]&&& &I_{j(1+j)}
  \end{tikzcd}
\] 
\end{document}