<field name="arch" type="xml">
<field name="product_manager" position="after">
<newline/>
+ <field name="supplier_taxes_id" colspan="3"/>
<field name="taxes_id" colspan="3"/>
</field>
</field>
<field name="arch" type="xml">
<field name="cost_method" position="after">
<newline/>
+ <field name="supplier_taxes_id" colspan="3"/>
<field name="taxes_id" colspan="3"/>
</field>
</field>