Could use some VB help with dealing with combo box data from a Union All query

[spOOk123]

I have a search form with multiple cascading combo boxes. Most combo boxes record sources are linked to a singular table field whereas I am using this code to filter results

Function SearchCriteria()
    Dim CustomerType As String
    Dim Task As String
    Dim strCriteria As String
    ' Example
    If Not IsNull(Me.cboBathTypes) Then 
        ' Baths
        CustomerType = CustomerType & " And ([BathTypes1] = '" & Me.cboBathTypes & "')"
    End If 
    strCriteria = CustomerType
    Task = "SELECT * FROM qry_Customer where " & strCriteria & " Order by CustomerName asc"
    Me.frm_ExtProducts_Subform1.Form.RecordSource = Task
    Me.frm_ExtProducts_Subform1.Form.Requery
End Function

My problem is that I have other combo boxes who's record sources are linked to a Union All query - whereas depending on the selection the data may be coming from [BathTypes1] or [BathTypes2] or [BathTypes3] and I am unable to figure out a working code I have tried so many variations including the following - (does not work)

If Not IsNull(Me.cboBathTypes) Then 
    ' Baths
    CustomerType = CustomerType & " And ([BathTypes1] = '" & Me.cboBathTypes & "')"
    Else
    CustomerType = CustomerType & " And ([BathTypes2] = '" & Me.cboBathTypes & "')"
    End If

My experience at coding is very limited and any help in the right direction is much appreciated