oca-ocb-l10n_americas/odoo-bringout-oca-ocb-l10n_ar/l10n_ar/views/uom_uom_view.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo>

    <record id="product_uom_tree_view" model="ir.ui.view">
        <field name="name">uom.uom.list</field>
        <field name="model">uom.uom</field>
        <field name="inherit_id" ref="uom.product_uom_tree_view"/>
        <field name="arch" type="xml">
            <list>
                <field name="l10n_ar_afip_code" optional="hide"/>
            </list>
        </field>
    </record>

    <record id="product_uom_form_view" model="ir.ui.view">
        <field name="name">uom.uom.form</field>
        <field name="model">uom.uom</field>
        <field name="inherit_id" ref="uom.product_uom_form_view"/>
        <field name="arch" type="xml">
            <div name="relative_factor" position="after">
                <field name="l10n_ar_afip_code" invisible="'AR' not in fiscal_country_codes"/>
            </div>
        </field>
    </record>
</odoo>