<filter string="Invoiced" domain="[('state','=',('invoiced'))]"/>
<filter string="Not Invoiced" domain="[('state','=',('paid'))]"/>
<separator/>
<filter string="Invoiced" domain="[('state','=',('invoiced'))]"/>
<filter string="Not Invoiced" domain="[('state','=',('paid'))]"/>
<separator/>