![alt text][1]
Aus [KOMA-Script-Homepage:][2]
    \documentclass[a4paper, oneside, 12pt]{scrbook} 
    %Seitenzahlen mittig, keine LEERSEITEN
    
    %\documentclass[a4paper, cleardoubleplain, oneside 12pt]{scrbook}
    %Seitenzahlen rechts und links, keine LEERSEITEN
    
        \usepackage[T1]{fontenc}
        \usepackage[utf8]{inputenc}
        \usepackage[ngerman]{babel}
        \usepackage{scrpage2}
        \usepackage{graphicx}
        \usepackage{xcolor}
        \usepackage{blindtext}
    
        \makeatletter
        %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
        %  DAUMENREGISTER
        %  Chapter thumbs with scrpage2
        %
         
        % Safty first
        \@ifundefined{chapter}{\let\chapter\undefined
          \chapter must be defined to use chapter thumbs!}{%
         
        % Two new commands for the width and height of the boxes with the
        % chapter number at the thumbs (use of commands instead of lengths
        % for sparing registers)
        \newcommand*{\chapterthumbwidth}{5em} %{2em}
        \newcommand*{\chapterthumbheight}{2em} %{1em}
         
        % Two new commands for the colors of the box background and the
        % chapter numbers of the thumbs
        \newcommand*{\chapterthumbboxcolor}{red} %{black}
        \newcommand*{\chapterthumbtextcolor}{yellow} %{white}
         
        % New command to set a chapter thumb. I'm using a group at this
        % command, because I'm changing the temporary dimension \@tempdima
        \newcommand*{\putchapterthumb}{%
          \begingroup
            \Large
            % calculate the horizontal possition of the right paper border
            % (I ignore \hoffset, because I interprete \hoffset moves the page
            % at the paper e.g. if you are using cropmarks)
            \setlength{\@tempdima}{\@oddheadshift}% (internal from scrpage2)
            \setlength{\@tempdima}{-\@tempdima}%
            \addtolength{\@tempdima}{\paperwidth}%
            \addtolength{\@tempdima}{-\oddsidemargin}%
            \addtolength{\@tempdima}{-1in}%
            % putting the thumbs should not change the horizontal
            % possition
            \rlap{%
              % move to the calculated horizontal possition
              \hspace*{\@tempdima}%
              % putting the thumbs should not change the vertical
              % possition
              \vbox to 0pt{%
                % calculate the vertical possition of the thumbs (I ignore
                % \voffset for the same reasons told above)
                \setlength{\@tempdima}{\chapterthumbwidth}%
                \multiply\@tempdima by\value{chapter}%
                \addtolength{\@tempdima}{-\chapterthumbwidth}%
                \addtolength{\@tempdima}{-\baselineskip}%
                % move to the calculated vertical possition
                \vspace*{\@tempdima}%
                % put the thumbs left so the current horizontal possition
                \llap{%
                  % and rotate them
                  \rotatebox{90}{\colorbox{\chapterthumbboxcolor}
                  {%
                      \parbox[c][\chapterthumbheight][c]{\chapterthumbwidth}{%
                        \centering
                        \textcolor{\chapterthumbtextcolor}{%
                          \strut\thechapter}\\
                      }%
                    }%
                  }%
                }%
                % avoid overfull \vbox messages
                \vss
              }%
            }%
          \endgroup
        }
         
        % New command, which works like \lohead but also puts the thumbs (you
        % cannot use \ihead with this definition but you may change this, if
        % you use more internal scrpage2 commands)
        \newcommand*{\loheadwithchapterthumbs}[2][]{%
          \lohead[\putchapterthumb#1]{\putchapterthumb#2}%
        }
         
        % initial use
        \loheadwithchapterthumbs{}
        \pagestyle{scrheadings}
         
        }
        %
        %  End of chapter thumbs with scrpage2
        %
        %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
        \makeatother
    
     %===========
    \begin{document}
    %===========
     
    \tableofcontents
     
    \part{Überschrift des 1. Teils}
    \chapter{Kapitel 1}
    \section{Abschnitt}
    \subsection{Unterabschnitt}
    \subsection{Unterabschnitt}
    \subsubsection{Unterunterabschnitt}
    \paragraph{Paragraph}
    \subparagraph{Unterparagraph}
     
    \subsection{Unterabschnitt}
     
    \chapter{Kapitel 2}
    \section{Abschnitt}
    \subsection{Unterabschnitt}
    \subsection{Unterabschnitt}
    \subsubsection{Unterunterabschnitt}
    \paragraph{Paragraph}
    \subparagraph{Unterparagraph} 
    
    \chapter{Kapitel 3}
    \section{Abschnitt}
    \subsection{Unterabschnitt}
    \subsection{Unterabschnitt}
    \subsubsection{Unterunterabschnitt}
    \paragraph{Paragraph}
    \subparagraph{Unterparagraph} 
    
    \part{Überschrift des 2. Teils}
    %===========
    \end{document}
    %===========
  [1]: http://texwelt.de/wissen/upfiles/aaaaaha22tf__--13-1215_03_1.pnghttp://texwelt.de/wissen/upfiles/aaaaaha22tf__--13-1215_03_1.png
  [2]: http://www.komascript.de/chapterthumbs-example