manufacture/mrp_bom_tracking/views/bom_template.xml

<?xml version="1.0" encoding="utf-8" ?>
<!-- Copyright 2019 ForgeFlow S.L. (https://www.forgeflow.com)
     License LGPL-3.0 or later (https://www.gnu.org/licenses/lgpl). -->
<odoo>
    <template id="track_bom_line_template">
        <div>
            <strong>The component quantities or UoMs have been updated.</strong>
            <ul>
                <t t-foreach="lines" t-as="line">
                    <li><t t-esc="line.product_id.display_name" />:</li>
                    Product Quantity: <t t-esc="line.product_qty" /><t
                        t-if='line.product_qty != product_qty'
                    > -&gt; <t t-esc="float(product_qty)" /></t><br />
                    Product Unit of Measure: <t
                        t-esc="line.product_uom_id.display_name"
                    /><t t-if='line.product_uom_id != product_uom_id'> -&gt; <t
                            t-esc="product_uom_id.display_name"
                        /></t><br />
                </t>
            </ul>
        </div>
    </template>
    <template id="track_bom_template">
        <div>
            <strong>The components have changed.</strong>
            <ul>
                <t t-foreach="lines" t-as="line">
                    <li><t t-esc="line.product_id.display_name" />: <t
                            t-esc="mode"
                        /> component<br /></li>
                    Product Quantity: <t t-esc="line.product_qty" /><br />
                    Product Unit of Measure: <t
                        t-esc="line.product_uom_id.display_name"
                    /><br />
                </t>
            </ul>
        </div>
    </template>
    <template id="track_bom_template_2">
        <div>
            <strong>The components have changed.</strong>
            <ul>
                <t t-foreach="lines" t-as="line">
                    <li><t t-esc="line.product_id.display_name" />:
                Removed component<br /></li>
                    <li><t t-esc="product_id.display_name" />:
                New component<br /></li>
                </t>
            </ul>
        </div>
    </template>
</odoo>