quant.xml

<?xml version="1.0" encoding="utf-8"?>
<openerp>
  <data>

    <!-- reorder Owner and Location to have Location then owner -->
    <!-- and add a name on Owner group by to be able to use it as default group by -->
    <record id="quant_search_view" model="ir.ui.view">
      <field name="name">quant_search_view</field>
      <field name="model">stock.quant</field>
      <field name="inherit_id" ref="stock.quant_search_view"/>
      <field name="arch" type="xml">
        <filter string='Owner' position="replace"/>

        <filter name="locationgroup" position="after">
           <filter name="ownergroup" string='Owner' context="{'group_by' : 'owner_id'}" groups="stock.group_tracking_owner"/>
        </filter>

        <filter name="internal_loc" position="after">
          <separator/> <!-- to get AND instead of OR between filters (WAT) -->
          <filter name="without_reservation" string="Available (without reservation)" domain="[('reservation_id','=', False)]"/>
        </filter>

      </field>
    </record>

  </data>
</openerp>