contract/product_contract/views/product_template.xml

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

<!--
    Copyright 2017 LasLabs Inc.
    Copyright 2018 ACSONE SA/NV.
    License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html).
-->

<odoo>

    <record id="product_template_form_contract_view" model="ir.ui.view">
        <field name="name">account.invoice.select.contract</field>
        <field name="model">product.template</field>
        <field name="inherit_id" ref="product.product_template_form_view"/>
        <field name="arch" type="xml">
            <xpath expr="//div[@name='options']" position="inside">
                <div attrs="{'invisible': [('type', '!=', 'service')],}">
                    <field name="is_contract"/>
                    <label for="is_contract"/>
                </div>
            </xpath>
            <xpath expr="//notebook" position="inside">
                <page string="Contract"
                      name="contract"
                      attrs="{'invisible': [('is_contract', '=', False)],}">
                    <group>
                        <field name="contract_template_id"
                               attrs="{'required':[('is_contract', '=', True)]}"/>
                    </group>
                    <group name="recurrence_info">
                        <group>
                            <field name="recurring_rule_type"/>
                        </group>
                        <group>
                            <field name="default_qty"/>
                            <field name="recurring_invoicing_type"/>
                        </group>
                    </group>
                    <group>
                        <field name="is_auto_renew"/>
                        <label for="termination_notice_interval" attrs="{'invisible': [('is_auto_renew', '=', False)],
                               'required':[('is_contract', '=', True)]}"/>
                        <div attrs="{'invisible': [('is_auto_renew', '=', False)],
                               'required':[('is_auto_renew', '=', True)]}">
                            <field name="termination_notice_interval"
                                   class="oe_inline" nolabel="1"/>
                            <field name="termination_notice_rule_type"
                                   class="oe_inline" nolabel="1"/>
                        </div>
                    </group>
                </page>
            </xpath>
        </field>
    </record>

</odoo>