I would like for the blue box (text3) to be below the other two boxes and to have the width of the other two boxes together. So basically I want to make the blue box (the large one in %Row2) wider without messing with the width measurements. Would that be possible?
Something like below=of node1 and node2 would do the trick but I haven't figured out a way to do it.
\documentclass{minimal}
\usepackage{tikz}
\usetikzlibrary{shapes,positioning}
\begin{document}
\begin{tikzpicture}[auto,
SmallBox/.style={rectangle, draw=black, fill=#1!20, minimum width=8em, align=center, minimum height=3em},
LargeBox/.style={rectangle, draw=black, fill=#1!20, minimum width=8em,align=center, minimum height=3em}
]
\matrix[row sep=0.5em]
{
% row 1
\node {}; & \node (cell32) {}; & \node {}; & \node (cell34) {}; & \node {}; & \node {}; \\
% row 2
\node {}; &
\node {}; &
\node {\tikz{
\node [SmallBox={red}] (node1) {text1};
\node [SmallBox={green}, right=of node1] (node2) {text2};
\node [LargeBox={blue}, below=of node2] (node3) {text3};
}}; &
\node {}; &
\node {}; &
\node {}; \\
};
% horizontal line
\draw [thick] (cell32.east) -- (cell34.west);
\end{tikzpicture}
\end{document}



fitto create a node which encloses the required nodes, and then thelet..insyntax to get that node width. Also you can omit thefitnode and measure instead the width of the desired nodes and add them inside thelet..inconstruct. – JLDiaz Mar 26 '13 at 17:06\CalcDistancein Replicate this chart using LaTeX, even if in this case maybe thefitlibrary is simpler. – Claudio Fiandrino Mar 26 '13 at 17:25backgroundslibrary already provides the right tools. – Qrrbrbirlbel Jul 19 '13 at 06:58