Draw TikZ arrow across multiple pages

Question

I want to have arrows between my marginnotes and I achieved this with \tikzmarknode (figure 1). But it does not work if one mark is on another page (figure 2).

What I would like to have is a continous line going down to the end of the page and then reappear on top of the next page (figure 3).

MWE:

\documentclass[10pt,oneside]{scrbook}
\usepackage{lipsum}
\usepackage[left=32.5mm, right=22.5mm, top=25mm, bottom=20mm, marginparsep=3mm]{geometry}
\usepackage{tikz}
    \usetikzlibrary{tikzmark}
\usepackage{marginnote}
\renewcommand*{\marginfont}{\footnotesize\itshape}

\begin{document}

\marginnote{\tikzmarknode{a}{Thermoplast}}
\lipsum[1]
\marginnote{\tikzmarknode{b}{teilkristallin}}
\lipsum[1]
\marginnote{\tikzmarknode{c}{aliphatisch}} 
\begin{tikzpicture}[remember picture, overlay, shorten >=1.5mm, shorten <=1.5mm,->]
    \draw ([xshift=10pt]a.south west) to ([xshift=10pt]b.north west);
    \draw ([xshift=10pt]b.south west) to ([xshift=10pt]c.north west);
\end{tikzpicture}
% \lipsum[1-6]    % Works fine
\lipsum[1-7]    % Doesn't work
\marginnote{\tikzmarknode{d}{aliphatisch}} 
\begin{tikzpicture}[remember picture, overlay, shorten >=1.5mm, shorten <=1.5mm,->]
    \draw ([xshift=10pt]c.south west) to ([xshift=10pt]d.north west);
\end{tikzpicture}

\end{document}

Answer 1

The tikzmark library comes with a check \iftikzmarkoncurrentpage. This allows us to distinguish the cases

1. none of the nodes on the current page (with the possibility that the current page is between two pages carrying subsequent marks that are to be connected),
2. first node on the current page,
3. second node on the current page,
4. both nodes on the same page.

These cases are distinguished in the macro \ConnectTikZmarknodes, which connects the nodes also over page breaks. It uses eso-pic to avoid requiring the user to add the macro on several pages. Thanks to the nice checks coming with tikzmark it is possible to (and, if the connection runs over more than one pages, also necessary) to add \ConnectTikZmarknodes before the nodes are actually defined.

\documentclass[10pt,oneside]{scrbook}
\usepackage{lipsum}
\usepackage[left=32.5mm, right=22.5mm, top=25mm, bottom=20mm, marginparsep=3mm]{geometry}
\usepackage{tikzpagenodes}
\usepackage{eso-pic}
\usetikzlibrary{tikzmark}
\usepackage{marginnote}
\renewcommand*{\marginfont}{\footnotesize\itshape}
\makeatletter
\newcommand\PageOfTikzmark[1]{%
\csname save@pg@\csname save@pt@\tikzmark@pp@name{#1}\endcsname\endcsname}
\makeatother
\newcommand{\ConnectTikZmarknodes}[3][]{\AddToShipoutPictureFG{%
\begin{tikzpicture}[remember picture, overlay, shorten >=1.5mm, 
    shorten <=1.5mm,#1]
\iftikzmark{#2}{\edef\pageA{\PageOfTikzmark{#2}}}{\edef\pageA{-1}}% 
\iftikzmark{#3}{\edef\pageB{\PageOfTikzmark{#3}}}{\edef\pageB{-1}}% 
\iftikzmarkoncurrentpage{#2}
\edef\myflag{1}%
\else
\edef\myflag{0}%
\fi 
\iftikzmarkoncurrentpage{#3}
\edef\myflag{\the\numexpr\myflag+2}%
\fi 
\ifcase\myflag
\or
 \draw[-] ([xshift=10pt]#2.south west)
     to ([xshift=10pt]#2.south west|-current page text area.south);
\or
 \draw[->] ([xshift=10pt]#3.north west|-current page text area.north) 
    to ([xshift=10pt]#3.north west);  
\or
 \draw[->] ([xshift=10pt]#2.south west)
     to ([xshift=10pt]#3.north west);
\fi
\ifnum\value{page}>\pageA
\ifnum\value{page}<\pageB
 \draw ([xshift=20pt]current page text area.north east) to
 ([xshift=20pt]current page text area.south east);
\fi
\fi
\end{tikzpicture}}}
\begin{document}

\marginnote{\tikzmarknode{a}{Thermoplast}}
\lipsum[1]
\marginnote{\tikzmarknode{b}{teilkristallin}}
\ConnectTikZmarknodes{a}{b}
\lipsum[1]
\marginnote{\tikzmarknode{c}{aliphatisch}} 
\ConnectTikZmarknodes{b}{c}
\lipsum[1-7]    % works fine
\marginnote{\tikzmarknode{d}{aliphatisch}} 
\ConnectTikZmarknodes{c}{d}
\ConnectTikZmarknodes{d}{e}
\lipsum[1-23]    
\marginnote{\tikzmarknode{e}{unproblematisch}} 
\end{document}