contract/agreement_maintenance/views/maintenance_equipment_view.xml

<!-- # Copyright (C) 2018 Pavlov Media
     # Copyright (C) 2019 Open Source Integrators
     # License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl). -->
<odoo>

    <record id="maintenance_equipment_form_view_agreement" model="ir.ui.view">
        <field name="name">maintenance.equipment.form.agreement</field>
        <field name="model">maintenance.equipment</field>
        <field name="inherit_id"
               ref="maintenance.hr_equipment_view_form"/>
        <field name="arch" type="xml">
            <xpath expr="//group/group[1]" position="inside">
                <field name="agreement_id"/>
            </xpath>
            <xpath expr="//notebook" position="inside">
                <page string="Services" id="services">
                    <field name="serviceprofile_ids"
                           domain="[('equipment_id', '=', False)]"
                           widget="many2many">
                        <tree>
                            <field name="name"/>
                            <field name="partner_id"/>
                            <field name="product_id"/>
                            <field name="stage_id"/>
                        </tree>
                    </field>
                </page>
            </xpath>
        </field>
    </record>

    <!-- Inherit maintenance equipment search view-->
    <record id="view_maintenance_equipment_filter_agreement" model="ir.ui.view">
        <field name="name">maintenance.equipment.select.agreement</field>
        <field name="model">maintenance.equipment</field>
        <field name="inherit_id"
               ref="maintenance.hr_equipment_view_search"/>
        <field name="arch" type="xml">
            <xpath expr="//group" position="inside">
                <filter string="Agreement" name="agreement_id" domain="[]"
                        context="{'group_by': 'agreement_id'}"/>
            </xpath>
        </field>
    </record>

</odoo>