Extract Unique Values Based On Dependant Combobox Selections

[Excel Fox]

Just made the necessary correction to your specific need, and didn't really look at the formatting of the code. Use this for the submit button

Private Sub BtnSubmit_Click()
Dim wsS As Worksheet
Dim wsR As Worksheet

Application.ScreenUpdating = False

Dim irow As Long, lngLoop As Long

Set wsS = Worksheets("Resultant")
'find first row in database
irow = wsS.Cells(Rows.Count, 1).End(xlUp).Offset(1, 0).Row
With wsS
For lngLoop = 0 To Me.ListStaIncNo.ListCount - 1
.Range("A" & irow + lngLoop).Value = Trim(Me.BxStaDistrict.Value)
.Range("B" & irow + lngLoop).Value = Trim(Me.BxStaTown.Value)
.Range("C" & irow + lngLoop).Value = Trim(Me.BxStaName.Value)
.Range("D" & irow + lngLoop).Value = Me.ListStaIncNo.List(lngLoop)
.Range("E" & irow + lngLoop).Value = Date
.Range("F" & irow + lngLoop).Value = Time
.Range("G" & irow + lngLoop).Value = Environ$("USERNAME")
Next lngLoop
End With

MsgBox "Data succesfully saved to database"

Application.StatusBar = False
Application.ScreenUpdating = True

End Sub

In addition, there's a fault with your listbox getting refreshed. The items has to be cleared first, before loading again with other criterias via the combobox. For that, I've added one line in this routine

Private Sub BxStaName_AfterUpdate()

    Dim Cl     As Range
    Dim ClAddress As String
    With Me
    With Sheets("Source")
        Set rSource = .Range(.Cells(1, 4), .Cells(.Rows.Count, 1).End(xlUp))
    End With
    'if no selection in OIC quit
        If .BxStaName.ListIndex < 0 Then Exit Sub
        Set Cl = rSource.Find(Me.BxStaName.Value, LookIn:=xlValues)
        If Not Cl Is Nothing Then
            ClAddress = Cl.Address
            Me.ListStaIncNo.Clear
            Do
                .ListStaIncNo.AddItem Cl.Offset(0, 1).Value
              
                Set Cl = rSource.FindNext(Cl)
            Loop While Not Cl Is Nothing And Cl.Address <> ClAddress
        End If
    End With
End Sub

And here's the file.

By the way, hope you've read the guidelines about forum cross posting.