from Spotfire.Dxp.Application.Filters import CheckBoxFilter
plFilter=Document.FilteringSchemes[0].Item[tab].Item[tab.Columns.Item["NETWORK"]].As[CheckBoxFilter]()
values = plFilter.Values
for value in plFilter.Values:
if plFilter.IsChecked(value):
plFilter.Uncheck(value)
else:
plFilter.Check(value)
