contract/agreement_legal/views/agreement_subtype.xml

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

    <!-- Agreement Sub Type List View-->
    <record model="ir.ui.view" id="partner_agreement_subtype_list_view">
        <field name="name">Agreement Subtype List</field>
        <field name="model">agreement.subtype</field>
        <field name="arch" type="xml">
            <tree default_order='name'>
                <field name="name" string="Sub-Type Name"/>
                <field name="agreement_type_id" string="Agreement Type"/>
            </tree>
        </field>
    </record>

    <!-- Agreement Sub Type Form View -->
    <record model="ir.ui.view" id="partner_agreement_subtype_form_view">
        <field name="name">Agreement Sub Type Form</field>
        <field name="model">agreement.subtype</field>
        <field name="arch" type="xml">
            <form string="Agreement Sub-Types">
                <sheet>
                    <div class="oe_title">
                        <label for="name" class="oe_edit_only"/>
                        <h1><field name="name"/></h1>
                    </div>
                    <group>
                        <group>
                        <field name="agreement_type_id"/>
                            </group>
                        <group></group>
                    </group>
                </sheet>
            </form>
        </field>
    </record>

    <!-- Actions opening views on models -->
    <record model="ir.actions.act_window" id="partner_agreement_action_subtype">
        <field name="name">Agreement Sub-Types</field>
        <field name="res_model">agreement.subtype</field>
        <field name="view_mode">tree,form</field>
    </record>

</odoo>