app-odoo/app_account_ztree/views/account_account_views.xml

<odoo>
    <data>
    <!-- list -->
        <record id="app_view_account_list" model="ir.ui.view">
            <field name="name">app.account.account.list.view</field>
            <field name="model">account.account</field>
            <field name="inherit_id" ref="account.view_account_list"/>
            <field name="arch" type="xml">
              <xpath expr="//tree" position="attributes">
                  <attribute name="default_order">code</attribute>
              </xpath>
                <xpath expr="field[@name='account_type']" position="after">
                    <field name="parent_id" optional="show"/>
                </xpath>
            </field>
        </record>

        <record id="app_view_account_form" model="ir.ui.view">
            <field name="name">app.account.account.form</field>
            <field name="model">account.account</field>
            <field name="inherit_id" ref="account.view_account_form"/>
            <field name="arch" type="xml">
              <xpath expr="//field[@name='account_type']" position="after">
                  <field name="parent_id" widget="ztree_select" options="{'ztree_name_field': 'display_name'}"/>
              </xpath>
            </field>
        </record>
    </data>
</odoo>