Personally, I got around this in a slightly different way - I had a pivot table querying an SQL server source and I was using the timeline slicer to restrict the results to a date range - I then wanted to summarise the pivot results in another table.
I selected the 'source' pivot table and created a named range called 'SourcePivotData'.
Create your summary pivot tables using the named range as a source.
In the worksheet events for the source pivot table, I put the following code:
Private Sub Worksheet_PivotTableUpdate(ByVal Target As PivotTable)
'Update the address of the named range
ThisWorkbook.Names("SourcePivotData").RefersTo = "='" & Target.TableRange1.Worksheet.Name & "'!" & Target.TableRange1.AddressLocal
'Refresh any pivot tables that use this as a source
Dim pt As PivotTable
Application.DisplayAlerts = False
For Each pt In Sheet2.PivotTables
pt.PivotCache.Refresh
Next pt
Application.DisplayAlerts = True
End Sub
Works nicely for me! :)