odoo16/addons/pos_hr/views/pos_order_report_view.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo>
    <record id="view_report_pos_order_search_inherit" model="ir.ui.view">
        <field name="name">report.pos.order.search.inherit</field>
        <field name="model">report.pos.order</field>
        <field name="inherit_id" ref="point_of_sale.view_report_pos_order_search"/>
        <field name="arch" type="xml">
            <xpath expr="//filter[@name='User']" position='after'>
                <filter string="Employee" name="employee_id" domain="[]" context="{'group_by':'employee_id'}"/>
            </xpath>
        </field>
    </record>

   <record id="report_pos_order_view_tree" model="ir.ui.view">
        <field name="name">report.pos.order.view.tree.inherit.pos.hr</field>
        <field name="model">report.pos.order</field>
        <field name="inherit_id" ref="point_of_sale.report_pos_order_view_tree"/>
        <field name="arch" type="xml">
            <field name="product_categ_id" position="after">
                <field name="employee_id" widget="many2one_avatar_employee"/>
            </field>
        </field>
    </record>
</odoo>