Try this code.

Option Explicit
  
  Private Sub CommandButton1_Click()  'Previous
Dim n               As Long
n = Me.ListBox1.ListCount - 1
      Select Case Me.ListBox1.ListIndex
          Case Is < 1
              Me.ListBox1.ListIndex = n
          Case Else
              Me.ListBox1.ListIndex = Me.ListBox1.ListIndex - 1
      End Select
End Sub
  
  Private Sub CommandButton2_Click()  'Next
Dim n               As Long
n = Me.ListBox1.ListCount - 1
      Select Case Me.ListBox1.ListIndex
          Case Is < n
              Me.ListBox1.ListIndex = Me.ListBox1.ListIndex + 1
          Case Else
              Me.ListBox1.ListIndex = 0
      End Select
End Sub
  
  Private Sub CommandButton3_Click()  'Search
Dim Search          As String
  Dim n               As Long
  Dim i               As Long
  Dim j               As Long
Search = Me.TextBox1.Text
      n = Len(Me.TextBox1)
      j = Me.ListBox1.ListCount - 1
      For i = 0 To j
          If Left(Me.ListBox1.List(i), n) = Search Then
              Me.ListBox1.Selected(i) = True
              Exit For
          End If
      Next
End Sub