Cfrgtkky

I used this answer to create a similar tree: https://tex.stackexchange.com/a/256753/175628

However the arrows do not align: with the joining lines:

Here is the forest code:

begin{figure}[H]

begin{center}

begin{forest}

  for tree={

    align=center,

    parent anchor=south,

    child anchor=north,

    font=sffamily,

    edge={thick, -{Stealth}},

    l sep+=10pt,

    edge path={

      noexpandpath [draw, forestoption{edge}] (!u.parent anchor) -- +(0,-10pt) -| (.child anchor)forestoption{edge label};

    },

    if level=0{

      inner xsep=0pt,

      tikz={draw [thick] (.south east) -- (.south west);}

    }{}

  }

  [Graphical User Interface

    [textbf{Drawing Functions}, name=A

      [textbf{Plot Pane}

        [textbf{Layer System}

          [textbf{Draw onto Canvas}]

          [textbf{Clear the Canvas}]

          [textbf{Bind Properties}]

        ]

      ]

    ]

    [Shared Layer Access, name=C]

    [Inputing Functions, name=B

      [Add Functions]

      [Remove Functions]

      [Modify Functions]

    ]

  ]

draw[-latex] (A) to[out=east,in=west] (C);

draw[-latex] (B) to[out=west,in=east] (C);

end{forest}

end{center}

caption{Graphical User Interface Hierarchical Diagram}

If the preamble is needed I will post it but it is the most horrible thing I have mashed together.

Welcome to TeX.SE! Are you looking for calign=child,calign child=2?

documentclass[tikz,border=3.14mm]{standalone}

usepackage[edges]{forest}

usetikzlibrary{arrows.meta}

begin{document}

begin{forest}

  for tree={

    align=center,

    calign=child,calign child=2,

    font=sffamily,

    edge+={thick, -{Stealth}},

    l sep'+=10pt,

    fork sep'=10pt,

  },

  forked edges,

  if level=0{

    inner xsep=0pt,

    tikz={draw [thick] (.children first) -- (.children last);}

  }{},

  [Graphical User Interface

    [textbf{Drawing Functions}, name=A

      [textbf{Plot Pane}

        [textbf{Layer System}

          [textbf{Draw onto Canvas}]

          [textbf{Clear the Canvas}]

          [textbf{Bind Properties}]

        ]

      ]

    ]

    [Shared Layer Access, name=C]

    [Inputing Functions, name=B

      [Add Functions]

      [Remove Functions]

      [Modify Functions]

    ]

  ]

draw[-latex] (A) to[out=east,in=west] (C);

draw[-latex] (B) to[out=west,in=east] (C);

end{forest}

end{document}