partner-contact/base_location/views/better_zip_view.xml

<?xml version="1.0" encoding="UTF-8"?>
<odoo>

    <record model="ir.ui.view" id="better_zip_form">
        <field name="name">res.better.zip.form</field>
        <field name="model">res.better.zip</field>
        <field name="arch" type="xml">
            <form string="City">
                <group col="4">
                <field name="name"/>
                <field name="code"/>
                <field name="city"/>
                <field name="state_id"/>
                <field name="country_id"/>
                </group>
            </form>
        </field>
    </record>

    <record model="ir.ui.view" id="better_zip_tree">
        <field name="name">res.better.zip.tree</field>
        <field name="model">res.better.zip</field>
        <field name="arch" type="xml">
            <tree string="Cities">
                <field name="name"/>
                <field name="code"/>
                <field name="city"/>
                <field name="state_id"/>
                <field name="country_id"/>
            </tree>
        </field>
    </record>

    <record id="view_better_zip_filter" model="ir.ui.view">
        <field name="name">res.better.zip.select</field>
        <field name="model">res.better.zip</field>
        <field name="arch" type="xml">
            <search string="Search city">
                <field name="name"/>
                <field name="code"/>
                <field name="city"/>
                <field name="state_id"/>
                <field name="country_id"/>
                    <group expand="0" string="Group By">
                        <filter string="State" domain="[]" context="{'group_by':'state_id'}"/>
                        <filter string="Country" domain="[]" context="{'group_by':'country_id'}"/>
                    </group>
            </search>
        </field>
    </record>

    <record id="action_zip_tree" model="ir.actions.act_window">
        <field name="name">Cites/locations</field>
        <field name="res_model">res.better.zip</field>
        <field name="view_type">form</field>
        <field name="view_mode">tree,form</field>
        <field ref="better_zip_tree" name="view_id"/>
        <field name="search_view_id" ref="view_better_zip_filter"/>
    </record>

    <menuitem
        name="Cities/Locations Management"
        id="locations_root_menu"
        parent="base.menu_custom"
        />

    <menuitem
        name="Cities/Locations"
        id="locations_menu"
        parent="locations_root_menu"
        action="action_zip_tree"
        />

</odoo>