manufacture/mrp_production_split/views/mrp_production.xml

<?xml version="1.0" encoding="utf-8" ?>
<!--
    Copyright 2023 Camptocamp SA (https://www.camptocamp.com).
    @author Iván Todorovich <ivan.todorovich@camptocamp.com>
    License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl).
-->
<odoo>

    <record id="mrp_production_form_view" model="ir.ui.view">
        <field name="model">mrp.production</field>
        <field name="inherit_id" ref="mrp.mrp_production_form_view" />
        <field name="arch" type="xml">
            <button name="action_serial_mass_produce_wizard" position="before">
                <button
                    name="action_split"
                    string="Split"
                    type="object"
                    attrs="{
                        'invisible': [
                            '|',
                            ('state', 'in', ('draft', 'done', 'to_close', 'cancel')),
                            ('product_qty', '&lt;=', 1),
                        ],
                    }"
                />
            </button>
        </field>
    </record>

</odoo>