Reference Pivot table filter

I am trying to reference a PIVOT table filter to use as the Save As name for generating a PDF. I cannot seem to find any combination of PIVOT table object reference to do this.

Sub Deferred_Rent_To_PDF()

Dim strWorksheet As String
Dim strPivotTable As String
Dim pdfFilename As Variant
Dim strDocName As String
Dim ptDeferredRent As pivotTable

strWorksheet = "Deferred"
strPivotTable = "DeferredRent" 

Set ptDeferredRent = Worksheets(strWorksheet).PivotTables(strPivotTable)
'strDocName = ptDeferredRent.                  <----- THIS IS WHERE I NEED HELP

pdfFilename = Application.GetSaveAsFilename(InitialFileName:=strDocName, _
    FileFilter:="PDF, *.pdf", Title:="Save As PDF")

    If pdfFilename <> False Then

    ActiveSheet.ExportAsFixedFormat _
        Type:=xlTypePDF, _
        Filename:=pdfFilename, _
        Quality:=xlQualityStandard, _
        IncludeDocProperties:=False, _
        IgnorePrintAreas:=False, _
        OpenAfterPublish:=True
    End If

End Sub