contract/contract_sale/views/account_analytic_contract_view.xml

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

    <record id="account_analytic_contract_view_form" model="ir.ui.view">
        <field name="name">Account Analytic Contract Form View (in
            sale_contract)
        </field>
        <field name="model">account.analytic.contract</field>
        <field name="inherit_id"
               ref="contract.account_analytic_contract_view_form"/>
        <field name="arch" type="xml">

            <xpath expr="//field[@name='discount']" position="attributes">
                <attribute name="groups">sale.group_discount_per_so_line
                </attribute>
            </xpath>

        </field>
    </record>

</odoo>