The shapes.multipart
library of TikZ
can be helpful (refer to Section 48.6
Shapes with Multiple Text Parts of the pgfmanual); a little example:
\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{shapes.multipart}
\begin{document}
\begin{tikzpicture}[
double/.style={draw, anchor=text, rectangle split,rectangle split parts=2},
triple/.style={draw, anchor=text, rectangle split,rectangle split parts=3}
]
\node[triple] {foo
\nodepart{second}
bar
\nodepart{third}
\tikz{\node[double] {\nodepart{second}baz};}
};
\node[triple] at (2.2,0) {some text here
\nodepart{second}
bar
\nodepart{third}
\tikz{\node[double] {\nodepart{second}some more text goes here};}
};
\node[double,align=center] at (7.5,0) {some text here
\nodepart{second}
bar \\
\tikz{\node[double,align=center] {\nodepart{second}some more text\\ goes here};}
};
\end{tikzpicture}
\end{document}
minimum height
andminimum width
are keys tikz recognises...