Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Column = 2 And Target.Row = 1 Then
    Dim iY1 As Long
    Dim iYz As Long
    Dim bFlag As Boolean
    Range(Cells(2, 3), Cells(Rows.Count, 3)).Clear
    
    With Sheets(1)
      bFlag = False
     On Error Resume Next
      iY1 = WorksheetFunction.Match(Target.Value, .Columns(3), 0) + 1
     If Err.Number = 0 Then bFlag = True
     On Error GoTo 0
     
     If bFlag Then
      iYz = 2
      While .Cells(iY1, 3).Value = ""
          Cells(iYz, 3).Value = .Cells(iY1, 1)
          iYz = iYz + 1
          iY1 = iY1 + 1
      Wend
     End If
     
    End With
End If
End Sub