documentclass[12pt,paper=a4]{scrartcl}
usepackage{forest}

begin{document}
begin{forest}
  for tree={
    circle,
    draw,
    minimum size = 1pt
    % font=tiny
  }
  [, phantom, for children={fit=band}, s sep'+=60pt
    [,
      [,
        [
          []
          []
        ]
        []
      ]
      [,
        []
        []
      ]
      [,
        []
        [,name=left
          []
          []
        ]
      ]
    ]
    [,
      [,
        [,name=right
          []
          []
        ]
        []
      ]
      [
          [,
            []
            []
          ]
          [,
            []
            [
              []
              []
            ]
          ]
        ]
    ]
  ]
  draw[-latex,double] (left) to (right);
end{forest}

end{document}

documentclass[12pt,paper=a4]{scrartcl}
usepackage{forest}

begin{document}
begin{forest}
  for tree={
    circle,
    draw,
    minimum size = 1pt
    % font=tiny
  }
  [, phantom, for children={fit=band}, s sep'+=60pt
    [,
      [,
        [
          []
          []
        ]
        []
      ]
      [,
        []
        []
      ]
      [,
        []
        [,name=left
          []
          []
        ]
      ]
    ]
    [,
      [,
        [,name=right
          []
          []
        ]
        []
      ]
      [
          [,
            []
            []
          ]
          [,
            []
            [
              []
              []
            ]
          ]
        ]
    ]
  ]
  draw[-latex,very thick,shorten <=5mm,shorten >=5mm] (left) to (right);
end{forest}

end{document}