Hi,

You can inherit the 'mrp.BomOverviewTable' template to add extra fields. For example:

<?xml version="1.0" encoding="UTF-8"?>
<templates xml:space="preserve">
<t t-name="custom_module.BomOverviewTable"
t-inherit="mrp.BomOverviewTable" t-inherit-mode="extension">
<xpath expr="//th[@name='th_mrp_bom_h']" position="after">
            <th>UOM</th>
        </xpath>
    </t>
<t t-name="custom_module.BomOverviewSpecialLine"
t-inherit="mrp.BomOverviewLine" t-inherit-mode="extension">
<xpath expr="//td[@name='td_mrp_bom']" position="after">
            <td t-esc="data.uom_name"/>
        </xpath>
    </t>
</templates>

Also, remember to add the XML file to your module's manifest file:
'assets': {
        'web.assets_backend': ['path/to/your/xml/file'],
    }

Hope it helps