Tikz foreach does not work well

You can add a label instead of the second node.

\documentclass{article} \usepackage{tikz} \usetikzlibrary{chains} \begin{document} \begin{tikzpicture}[thick, snode/.style={draw,fill=black,circle,scale=2}, every node/.style={inner sep=1pt}, ] \begin{scope}[xshift=0cm,yshift=0cm,start chain=going right,node distance=7mm] \foreach \i in {1,...,5} \node[snode,on chain,label=above:1] (g\i) {}; % \node [above=0.1cm of g\i] (y\i) {1}; %Missing \endcsname, Extra \endcsname \end{scope} \begin{scope}[xshift=0cm,yshift=-5cm,start chain=going right,node distance=7mm] \foreach \i in {1,...,5} \node[snode,on chain,label=below:2] (h\i) {}; % \node [below = 0.1cm of h\i] (z\i) {2}; %problem with \endcsname \end{scope} \foreach \i in {1,...,5} \foreach \j in {1,...,5} \draw (g\i) -- (h\j); \end{tikzpicture} \end{document} 

You may be interested in the graphdrawing capabilities of TikZ 3. Below is a simple example. It doesn't reproduce the style of your code though, only the structure.

\documentclass{article} \usepackage{tikz} \usetikzlibrary{graphdrawing,graphs} \usegdlibrary{layered} \begin{document} \begin{tikzpicture} \graph [layered layout,grow=down,sibling distance=2cm,layer distance=4cm]{ {a,b,c,d,e} --[complete bipartite] {f,g,h,i,j} }; \end{tikzpicture} \end{document}