class hr_employee(osv.osv):
_inherit = 'hr.employee'
_columns = {
'badge_number':fields.char('B/No',required=True),
}
hr_employee()
<record model='ir.ui.view' id='hr_model_search'>
<field name="name">hr.model.search</field>
<field name="model">hr.employee</field>
<field name="type">search</field>
<field name="arch" type="xml">
<search string="Badge Number" >
<field name="badge_number" /> #cannot search custom badge number
</search>
</field>
</record>