<odoo>
  <data>
    <!--Inherit quotations search view-->
    <record id="view_sale_order_inherit_search" model="ir.ui.view">
      <field name="name">sale.order.search.expand.filter</field>
      <field name="model">sale.order</field>
      <field name="inherit_id" ref="sale.sale_order_view_search_inherit_quotation"/>
      <field name="arch" type="xml">
        <xpath expr="//search" position="inside">
          <!-- This field will show up on the default filters -->
          <filter string="Total &lt; 1000" name="total_under_1000" domain="[('amount_total', '&lt;', 1000)]"/>
          <filter string="Total &gt;= 1000" name="total_above_1000" domain="[('amount_total', '&gt;=', 1000)]"/>
        </xpath>
      </field>
    </record>
  </data>
</odoo>

<odoo>
  <data>
    <!--Inherit quotations search view-->
    <record id="view_sale_order_inherit_search" model="ir.ui.view">
      <field name="name">sale.order.search.expand.filter</field>
      <field name="model">sale.order</field>
      <field name="inherit_id" ref="sale.sale_order_view_search_inherit_quotation"/>
      <field name="arch" type="xml">
        <xpath expr="//search" position="inside">
          <!-- This field will show up on the default filters
               &lt; is the XML encoding for < and &gt; is the XML encoding for > -->
          <filter string="Total &lt; 1000" name="total_under_1000" domain="[('amount_total', '&lt;', 1000)]"/>
          <filter string="Total &gt;= 1000" name="total_above_1000" domain="[('amount_total', '&gt;=', 1000)]"/>
        </xpath>
      </field>
    </record>
  </data>
</odoo>

Add comment about XML encoding
[IMP] Add comment about XML encoding
