I have 4 nodes, and I need to draw an arrow that turns 2 times from a node to another node.
\documentclass[tikz,border=5pt]{standalone}
\usepackage{tikz}
\usetikzlibrary{shapes.geometric, arrows}
\begin{document}
\tikzstyle{process} = [rectangle, minimum width=3cm, minimum height=1cm, text centered, draw=black, fill=orange!30]
\tikzstyle{decision} = [diamond, minimum width=3cm, minimum height=1cm, text centered, draw=black, fill=green!30]
\tikzstyle{arrow} = [thick,->,>=stealth]
\begin{tikzpicture}[node distance=2cm]
\node (pro1) [process] {Process 1};
\node (dec1) [decision, below of=pro1, yshift=-0.5cm] {Decision 1};
\node (pro2b) [process, right of=dec1, xshift=2cm] {Process 2b};
\node (pro3b) [process, above of=pro2b] {Process 2a};
\draw [arrow] (pro1) -- (dec1);
\draw [arrow] (dec1) -| (pro3b) ;
\end{tikzpicture}
\end{document}


\draw [arrow] (dec1.east) -- + (0.5,0) |- (pro3b) ;instead of\draw [arrow] (dec1) -| (pro3b);. – Zarko May 08 '16 at 18:14