odoo16/odoo/addons/base/views/res_country_views.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo>
    <data>
        <!--
        Country
        -->
        <record id="view_country_tree" model="ir.ui.view">
            <field name="name">res.country.tree</field>
            <field name="model">res.country</field>
            <field name="arch" type="xml">
                <tree string="Country" create="0" delete="0">
                    <field name="name"/>
                    <field name="code"/>
                </tree>
            </field>
        </record>

        <record id="view_country_form" model="ir.ui.view">
            <field name="name">res.country.form</field>
            <field name="model">res.country</field>
            <field name="arch" type="xml">
                <form create="0" delete="0">
                    <sheet>
                        <div class="oe_button_box" name="button_box">
                        </div>
                        <field name="image_url" widget="image_url" class="oe_avatar" options="{'size': [128,128]}"/>
                        <group name="main_group">
                            <group name="country_details">
                                <field name="name"/>
                                <field name="currency_id"/>
                                <field name="code" required="1"/>
                            </group>
                            <group name="phone_vat_settings">
                                <field name="phone_code" options="{'format': false}"/>
                                <field name="vat_label"/>
                                <field name="zip_required"/>
                                <field name="state_required"/>
                            </group>
                        </group>
                        <group name="advanced_address_formatting" string="Advanced Address Formatting" groups="base.group_no_one">
                            <label for="address_view_id"/>
                            <div class="o_row">
                                <field name="address_view_id"/>
                                <div class="text-muted ms-2">Choose a subview of partners that includes only address fields, to change the way users can input addresses.</div>
                            </div>
                            <label for="address_format"/>
                            <div class="o_row">
                                <field name="address_format" placeholder="Address format..."/>
                                <div name="div_address_format ms-2" class="text-muted">Change the way addresses are displayed in reports</div>
                            </div>
                            <field name="name_position" class="oe_inline"/>
                        </group>
                        <label for="state_ids"/>
                        <field name="state_ids">
                            <tree editable="bottom">
                                <field name="name"/>
                                <field name="code"/>
                            </tree>
                        </field>
                    </sheet>
                </form>
            </field>
        </record>

        <record id="action_country" model="ir.actions.act_window">
            <field name="name">Countries</field>
            <field name="type">ir.actions.act_window</field>
            <field name="res_model">res.country</field>
            <field name="help" type="html">
                <p class="o_view_nocontent_smiling_face">
                    No Country Found!
                </p><p>
                    Manage the list of countries that can be set on your contacts.
                </p>
            </field>
        </record>

        <record id="view_country_group_tree" model="ir.ui.view">
            <field name="name">res.country.group.tree</field>
            <field name="model">res.country.group</field>
            <field name="arch" type="xml">
                <tree string="Country Group">
                    <field name="name"/>
                </tree>
            </field>
        </record>

        <record id="view_country_group_form" model="ir.ui.view">
            <field name="name">res.country.group.form</field>
            <field name="model">res.country.group</field>
            <field name="arch" type="xml">
                <form string="Country Group">
                    <sheet>
                        <div class="oe_title">
                            <label for="name" string="Group Name"/>
                            <h1><field name="name" placeholder="e.g. Europe"/></h1>
                        </div>
                        <group name="country_group">
                            <field name="country_ids" widget="many2many_tags" options="{'no_open': True, 'no_create': True}"/>
                        </group>
                    </sheet>
                </form>
            </field>
        </record>

        <record id="action_country_group" model="ir.actions.act_window">
            <field name="name">Country Group</field>
            <field name="type">ir.actions.act_window</field>
            <field name="res_model">res.country.group</field>
            <field name="help" type="html">
                <p class="o_view_nocontent_smiling_face">
                    Create a Country Group
                </p><p>
                    Use groups to organize countries that are frequently selected together (e.g. "LATAM", "BeNeLux", "ASEAN").
                </p>
            </field>
        </record>

        <!-- State -->
        <record id="view_country_state_tree" model="ir.ui.view">
            <field name="name">res.country.state.tree</field>
            <field name="model">res.country.state</field>
            <field name="arch" type="xml">
                <tree string="State" editable="bottom">
                    <field name="name"/>
                    <field name="code"/>
                    <field name="country_id" options="{'no_create': True, 'no_open': True}"/>
                </tree>
            </field>
        </record>

        <record id="view_country_state_form" model="ir.ui.view">
            <field name="name">res.country.state.form</field>
            <field name="model">res.country.state</field>
            <field name="arch" type="xml">
                <form string="State">
                    <sheet>
                        <group>
                            <field name="name"/>
                            <field name="code"/>
                            <field name="country_id" options='{"no_open": True, "no_create": True}'/>
                        </group>
                    </sheet>
                </form>
            </field>
        </record>

        <record id="view_country_state_search" model="ir.ui.view">
            <field name="name">res.country.state.search</field>
            <field name="model">res.country.state</field>
            <field name="arch" type="xml">
                <search string="Country">
                    <field name="name"/>
                    <field name="country_id"/>
                    <group string="Group By">
                        <filter name="groupby_country" string="Country" context="{'group_by': 'country_id'}"/>
                    </group>
                </search>
            </field>
        </record>

        <record id="action_country_state" model="ir.actions.act_window">
            <field name="name">Fed. States</field>
            <field name="type">ir.actions.act_window</field>
            <field name="res_model">res.country.state</field>
            <field name="view_id" ref="view_country_state_tree"/>
            <field name="help" type="html">
                <p class="o_view_nocontent_smiling_face">
                    Create a State
                </p><p>
                    Federal States belong to countries and are part of your contacts' addresses.
                </p>
            </field>
        </record>

    </data>
</odoo>