穿过两棵树的箭头 Tikz

Question

如何在两棵树之间添加虚线，如下图所示，

\begin{center}
\begin{tabular}{p{4cm}p{4cm}}
\tikzset{my dbl/.style={double,double distance=2pt}}
\centering
\begin{forest}
for tree={edge=thick,calign=fixed edge angles}
[a
[b
 [b,edge=my dbl] 
 [$\ast$
 [d]
 ]
 ]
]
   %[\subnode{marke}{e},draw,dashed]
\end{forest} &
\tikzset{my dbl/.style={double,double distance=2pt}}
\centering
\begin{forest}
for tree={edge=thick,calign=fixed edge angles}
[\subnode{markh}{a},name=a,tikz={\node [fit=() (!1)]}
 [b,edge=my dbl
 [d]
 ]
 [$\ast$
 [d,edge=my dbl]
 ]
]
\end{forest}

\end{tabular}
\begin{tikzpicture}[overlay,remember picture]
\draw[green](marke.east)--(markh.west);
%\draw [-stealth](a) to[bend right] (b.west);
\end{tikzpicture}
\end{center}

这是我目前的代码。没有任何效果。

Answer 1

正如解释的那样这个答案，您可以使用\subnodes，它们在您的代码中已经存在（但已被注释掉）。

\documentclass{article}
\usepackage[edges]{forest}
\usetikzlibrary{tikzmark}
\begin{document}
\begin{center}
\begin{tabular}{p{4cm}p{4cm}}
\tikzset{my dbl/.style={double,double distance=2pt}}
\centering
\begin{forest}
for tree={edge=thick,calign=fixed edge angles}
[\subnode{marka1}{a}
[b
 [b,edge=my dbl] 
 [$\ast$
 [d]
 ]
 ]
]
\end{forest} &
\tikzset{my dbl/.style={double,double distance=2pt}}
\centering
\begin{forest}
for tree={edge=thick,calign=fixed edge angles}
[\subnode{marka2}{a}
 [b,edge=my dbl
 [d]
 ]
 [$\ast$
 [d,edge=my dbl]
 ]
]
\end{forest}
\end{tabular}
\end{center}
\begin{tikzpicture}[overlay,remember picture]
\draw[dashed,-latex] (marka2) to[bend right] (marka1);
\end{tikzpicture}
\end{document}