\documentclass[12pt]{standalone}
\input{header}
\usepackage[edges]{forest}
\usetikzlibrary{shadows.blur,arrows.meta}
\pagestyle{empty}
\def\name#1{\textsf{\it #1}}
\tikzset{concept/.style={rectangle split,rectangle split parts=1,draw,
    fill=white,blur shadow,rounded corners,align=center}}
\begin{document}
\begin{forest}
    [,phantom,for tree={concept,edge={-Stealth}}
      [,phantom
        [\name{AosLeftSideTraits\_2}
           [,phantom]
          [\name{AosIdentifiedVerticalTraits\_2},name=ivt]
        ]
        [\name{AosRightSideTraits\_2},name=rst]
      ]
      [,phantom
        [\name{AosBottomSideTraits\_2}
           [,phantom]
           [\name{AosIdentifiedHorizontalTraits\_2},name=iht]
        ]
        [\name{AosTopSideTraits\_2},name=tst]
      ]
    ]
    \draw[-Stealth] (rst) to (ivt);
    \draw[-Stealth] (tst) to (iht);
  \end{forest}
\end{document}
