contract/contract_sale/views/res_partner_view.xml

<?xml version="1.0" encoding="utf-8" ?>
<odoo>
    <record id="view_partner_form" model="ir.ui.view">
        <field name="inherit_id" ref="contract.view_partner_form" />
        <field name="model">res.partner</field>
        <field type="xml" name="arch">
            <field name="customer_rank" position="attributes">
                <attribute name="groups" add="sales_team.group_sale_salesman" />
            </field>
            <xpath expr="//button[@name='act_show_contract']" position="attributes">
                <attribute name="groups" add="sales_team.group_sale_salesman" />
            </xpath>
            <field name="supplier_rank" position="attributes">
                <attribute name="groups" add="sales_team.group_sale_salesman" />
            </field>
        </field>
    </record>
</odoo>