contract/agreement_legal_sale/views/agreement.xml

<!-- Copyright 2019 Open Source Integrators
     License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl). -->
<odoo>

    <!-- Agreement Form View -->
    <record id="agreement_sale_form_view" model="ir.ui.view">
        <field name="name">agreement.form.view</field>
        <field name="model">agreement</field>
        <field name="inherit_id" ref="agreement_legal.partner_agreement_form_view" />
        <field name="arch" type="xml">
            <page name="signature" position="after">
                <page name="sales" string="Sales">
                    <group>
                        <group id="sale_left">
                            <field name="sale_id" readonly="1" />
                            <field name="analytic_account_id" />
                        </group>
                        <group id="sale_right" />
                    </group>
                </page>
            </page>
        </field>
    </record>

    <menuitem
        id="agreement.agreement_menu"
        action="agreement.agreement_action"
        sequence="100"
    />

</odoo>