\documentclass{article}
\usepackage[all]{xy}
\usepackage{xepersian}
\settextfont[Scale=1.1]{XB Niloofar}
\setdigitfont[Scale=1.1]{XB Zar}
\setlatintextfont{Junicode}
\defpersianfont\nastaliq[Scale=1.2]{IranNastaliq}
\newcommand{\XX}{\mathbf{X}^{\bullet}}
\newcommand{\YY}{\mathbf{Y}^{\bullet}}

\begin{document}
\[\xymatrix@C+1pc{A :\ar[d]_{f}\cdots \ar[r] & X_{n+1}  \ar[r]^{d_{n+1}^{\XX}}  \ar[d]_{f_{n+1}}  & X_n \ar[r]^{d_n^{\XX}}\ar[d]_{f_n} & X_{n-1} \ar[r] \ar[d]_{f_{n-1}} &
\cdots \\ B :\cdots \ar[r] & Y_{n+1} \ar[r]_{{d}_{n+1}^{\YY}} & Y_{n} \ar[r]_{{d}_{n}^{\YY}} & Y_{n-1}\ar[r] & \cdots} \]
\end{document}