Macro to Copy duplicate values from a column to a separate sheet

like this?

Sub xxx()
Dim a As Object, b, c, rw As Long

Set a = CreateObject("scripting.dictionary")
a.comparemode = vbTextCompare
Sheets("raw data").Activate
rw = Cells(Rows.Count, "aa").End(3).Row
b = Cells(1, "aa").Resize(rw)
For c = 2 To rw
    a(b(c, 1)) = a(b(c, 1)) + 1
Next c

For Each c In a.keys
    If a(c) < 5 Then a.Remove c
Next c

If a.Count > 0 Then
    With Sheets("analysis")
        .Cells(2, 1).Resize(a.Count, 2) = _
            Application.Transpose(Array(a.keys, a.items))
        .Cells(1, 1) = b(1, 1)
        .Cells(1, 2) = "count if>=5"
    End With
Else
    MsgBox "None are >=5"
End If

End Sub