hr_expense_onchange/views/hr_expense_views.xml
<?xml version="1.0" encoding="utf-8" ?>
<!-- Copyright 2019 OpenSynergy Indonesia
License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl-3.0) -->
<openerp>
<data>
<record id="hr_expense_view_form" model="ir.ui.view">
<field name="name">hr.expense form</field>
<field name="model">hr.expense.expense</field>
<field name="inherit_id" ref="hr_expense.view_expenses_form" />
<field name="arch" type="xml">
<data>
<xpath expr="//field[@name='currency_id']" position="attributes">
<attribute name="on_change" />
</xpath>
<xpath expr="//field[@name='employee_id']" position="attributes">
<attribute name="on_change" />
</xpath>
</data>
</field>
</record>
</data>
</openerp>