I have added a custom variable I need to make it as the searchable one I need to add the code segment ,

example:- Name = x_RDClass ;  Label = Class 

where I can get this thing in Odoo "product_search_form_view" to make a custom field searchable ?

To add this code:-

<record model="ir.ui.view" id="product_search_form_view_inherit">

<field name="name">product.search.form.inherit</field>

<field name="model">product.product</field>

<field name="inherit_id" ref="product.product_search_form_view"/>

<field name="type">search</field>

<field name="arch" type="xml">

<field name="name" position="replace">

<field name="name" string="Product" filter_domain="['|', ('name','ilike',self), '|', ('default_code','ilike',self), '|', ('commat','ilike',self), '|', ('x_RDClass','ilike',self), '|', ('manufacturer','ilike',self), ('description','ilike',self)]"/>

</field>

</field>

</record>