documentclass{article}
usepackage{forest}
usetikzlibrary{positioning,arrows.meta}

newsaveboxDowntree
newsaveboxUptree

saveboxDowntree{begin{forest}
for tree={
  s sep=25pt,
  l sep=20pt,
  where n children=0{}{draw,circle},
  edge={->,>=latex}
}
[Y3
  [Y2,edge label={node[text width=15pt,midway,left,font=strutscriptsize]{yes}}
    [,edge label={node[text width=15pt,midway,left,font=strutscriptsize]{yes}}]
    [,edge label={node[text width=15pt,midway,right,font=strutscriptsize]{no}}]
  ]
  [Y1,edge label={node[text width=15pt,midway,right,font=strutscriptsize]{no}}
    [,edge label={node[text width=15pt,midway,left,font=strutscriptsize]{yes}}]
    [,edge label={node[text width=15pt,midway,right,font=strutscriptsize]{no}}]
  ]
]
end{forest}%
}
saveboxUptree{begin{forest}
for tree={
  grow'=north,
  s sep=25pt,
  l sep=20pt,
  where n children=0{}{draw,circle},
  edge={->,>=latex}
}
[X3
  [X4,edge label={node[text width=15pt,midway,left,font=strutscriptsize]{no}}
    [,edge label={node[text width=15pt,midway,left,font=strutscriptsize]{no}}]
    [,edge label={node[text width=15pt,midway,right,font=strutscriptsize]{yes}}]
  ]
  [X1,edge label={node[text width=15pt,midway,right,font=strutscriptsize]{yes}}
    [,edge label={node[text width=15pt,midway,left,font=strutscriptsize]{no}}]
    [,edge label={node[text width=15pt,midway,right,font=strutscriptsize]{yes}}]
  ]
]
end{forest}%
}

begin{document}

begin{tikzpicture}[>={Latex[open]}]
node[inner sep=0pt] (Down) {useboxDowntree};
node[inner sep=0pt,below=0pt of Down] (Up) {useboxUptree};
begin{scope}[red,->]
draw
  ([xshift=-15pt,yshift=-10pt]Down.north) to[bend right] (Down.south west);
draw
  ([xshift=15pt,yshift=-10pt]Down.north) to[bend left] (Down.south east);
draw
  ([xshift=-15pt,yshift=10pt]Up.south) to[bend left] (Up.north west);
draw
  ([xshift=15pt,yshift=10pt]Up.south) to[bend right] (Up.north east);
end{scope}
begin{scope}[green,<->]
draw
  ([xshift=-2pt]Down.south)
  .. controls ++(-10pt,2cm) and ++(10pt,2cm) ..
  ([xshift=2pt]Down.south);
draw
  ([xshift=-2pt]Up.north)
  .. controls ++(-10pt,-2cm) and ++(10pt,-2cm) ..
  ([xshift=2pt]Up.north);
end{scope}

end{tikzpicture}

end{document}