This seems to work. I am unsure why my PivotFields name and Items are with the [].

Sub Filter_Single_Item()
   Dim pt as PivotTable, pf As PivotField, ws As Worksheet
   
   Set ws = ThisWorkbook.Worksheets ("Sheet1")
   Set pt = ws.PivotTables("pvt_1")
   Set pf = pt.PivotFields("[Table1].[filter1].[filter1]")

   pf.ClearAllFilters

   pf.VisibleItemsList = Array("[Table1].[filter1].&[item1]")
End Sub