project.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo>
    <record id="edit_project_product" model="ir.ui.view">
        <field name="name">project.product.form</field>
        <field name="model">project.project</field>
        <field name="inherit_id" ref="project.edit_project"/>
        <field name="type">form</field>
        <field name="arch" type="xml">
            <page name="settings" position="after">
                <page string="Product">
                    <field name="product_ids">
                        <tree editable="bottom">
                            <field name="product_id"/>
                        </tree>
                    </field>
                </page>
            </page>
        </field>
    </record>
</odoo>