I want to have a figure or table that looks like this:
I found a similar structure on this thread: Creating a graphical representation of a table of contents in TikZ
I might quote the code from there:
\documentclass[border=2pt,tikz]{standalone}
\usetikzlibrary{calc,positioning,backgrounds,fit}
\renewcommand{\rmdefault}{ptm}
\begin{document}
\newcommand{\ut}{4mm}
\begin{tikzpicture}[bk/.style args={#1}{draw,fill=gray!20,minimum height=2.7*\ut,minimum width=#1*\ut,align=center}, part/.style={inner sep=0pt,outer sep=0pt,font={\Large\bfseries}, white,align=left, xshift=-8*\ut}, node distance=.5*\ut]
\node[bk=30](c1){Chapter 1\\\textit{Chapter 1 Title}};
\node[bk=9.75,below=of c1.south west, anchor=north west](c2){Chapter 2\\\textit{Chapter 2 Title}};
\node[bk=19.75,below=of c1.south east, anchor=north east](c3){Chapter 3\\\textit{Chapter 3 Title}};
\node[part,left=of {$(c1.west)!.5!(c2.west)$},anchor=west](P1){Part I\\\textit{Part I Title}};
\begin{scope}[on background layer]
\node[rectangle,fill=gray!70,fit=(c1)(c2)(P1),inner sep=10pt] {};
\end{scope}
\node[bk=30,below=of c2.south west,anchor=north west,yshift=-2em](c1){Chapter 4\\\textit{Chapter 4 Title}};
\node[bk=30,below=of c1.south west, anchor=north west](c2){Chapter 5\\\textit{Chapter 5 Title}};
\node[bk=30,below=of c2.south east, anchor=north east](c3){Chapter 6\\\textit{Chapter 6 Title}};
\node[part,left=of {$(c1.west)!.5!(c3.west)$},anchor=west](P2){Part II\\\textit{Part II Title}};
\begin{scope}[shift={(0,-10*\ut)},on background layer]
\node[rectangle,fill=gray!70,fit=(c1)(c3)(P2),inner sep=10pt] {};
\end{scope}
\node[bk=30,below=of c3.south,anchor=north,yshift=-2em](c1){Chapter 7\\\textit{Chapter 7 Title}};
\node[bk=9.75,below=of c1.south west, anchor=north west](c2){Chapter 8\\\textit{Chapter 8 Title}};
\node[bk=9.75,below=of c1.south east, anchor=north east](c3){Chapter 10\\\textit{Chapter 10 Title}};
\node[bk=9.5,left=of c3.west, anchor=east](c4){Chapter 9\\ \textit{Chapter 9 Title}};
\node[part,left=of {$(c1.west)!.5!(c2.west)$},anchor=west](P3){Part III\\\textit{Part III Title}};
\begin{scope}[shift={(0,-24*\ut)},on background layer]
\node[rectangle,fill=gray!70,fit=(c1)(c2)(P3),inner sep=10pt] {};
\end{scope}
\end{tikzpicture}
\end{document}
How can I modify this code so that it looks like the structure I want to have? Many thanks in advance.


\node[part,left=of ...). In addition, it puts some nodes below at the left and at the right of another one (see\node[bk=9.75,below=of c1.south west ...and\node[bk=19.75,below=of c1.south east ...) -- You may check how to create TikZ nested nodes – Jaime Sep 16 '17 at 16:00tcolorboxrather than trying to reinvent ice skates. – cfr Sep 16 '17 at 22:33tikz-arrowstag? – Ignasi Sep 21 '17 at 07:11