eiru_reports_commission_by_seller/views/menus.xml

<?xml version="1.0" encoding="UTF-8"?>
<openerp>
  <data>
    <!-- main menu name -->
    <menuitem id="report_commission_parent_menu" name="Comisión" parent="eiru_reports.eiru_reports_main_menu" sequence="10"/>

    <!-- sub menu -->

    <menuitem id="salesman_commission_menu" parent="report_commission_parent_menu" name="Comisión por vendedor" action="salesman_commission_action" sequence="1"/>

  </data>
</openerp>