The code segment will naturally be added to the silkworm_view.xml file. It will have the same record structure as our other modification. Adding this code segment and updating the module will implement the change we want:

<record id="sale_view_sales_order_filter" model="ir.ui.view"> 
    <field name="name">sale.order.search</field> 
    <field name="model">sale.order</field> 
    <field name="inherit_id" ref="sale.view_sales_order_filter"/> 
    <field name="arch" type="xml"> 
      <field name="name" position="after"> 
        <filter name="rush" string="Rush Only" 
         domain="[('rush','=',True)]"/> 
      </field> 
    </field> 
</record> 

Let's look at some of the more important elements of this code segment. It follows a similar structure to the modification that added fields to our form. What is most important when looking at the code in any module is to identify the inherit_id field's ref value. This is what ties your view modifications to the view in the base module.

In this case, our inherit_id is sale.view_sales_order_filter.