You lost me. I don't know what the textbox control name is. I don't know what column of data you want to filter in it.
Post #13's 1st userform has the code similar to post #10.
Private Sub UserForm_Initialize()
Dim a
a = Application.Index(Range("A2", Cells(Rows.Count, "A").End(xlUp)).Value, 0, 0)
ComboBox1.List = a
End Sub
Private Sub ComboBox1_Change()
Dim a, b
On Error Resume Next
a = Application.Transpose(Range("A2", Cells(Rows.Count, "A").End(xlUp)))
With ComboBox1
If .Value = "" Then .List = a
'b = Filter(Application.Transpose(.List), .Text, True, vbTextCompare)
b = Filter(a, .Text, True, vbTextCompare)
If UBound(b) <> -1 Then .List = Application.Transpose(b)
End With
End Sub