base_location/views/state_view.xml

<?xml version="1.0"?>
<openerp>
    <data>
        <!-- Add cities to the State form -->
        <record model="ir.ui.view" id="view_country_state_form2">
            <field name="name">view_country_state_form2</field>
            <field name="model">res.country.state</field>
            <field name="inherit_id" ref="base.view_country_state_form"/>
            <field name="arch" type="xml">
                <field name="country_id" position="after">
                    <field name="better_zip_ids"
                        context="{'country_id': country_id}"
                        colspan="4"
                        nolabel="1">
                        <tree editable="top">
                            <field name="name"/>
                            <field name="code"/>
                            <field name="city"/>
                            <field name="country_id"/>
                        </tree>
                    </field>
                </field>
            </field>
        </record>
    </data>
</openerp>