Hello , 

First Create Group Using Below Code :

<record model="res.groups" id="group_user_hide" >
        <field name="name">Hide User</field>
</record>

If you want to Employ Menu for Specific Group Than Try Below Code For Example in Sale order:

<menuitem id="menu_sale_config"
            name="Configuration"
            parent="sale_menu_root"
            sequence="6"
            groups="Module.group_user_hide"/>

Thanks

Hello 

Create one group and that group assign on the HR main manu

<record model="res.groups" id="group_hr_menu" >
        <field name="name">Group HR Menu</field>
</record>

now assign above group on the HR Root menu

<record id="hr.menu_hr_root" model="ir.ui.menu" >
     <field name="groups_id" eval="[(6, 0, [ref('module_name.group_hr_menu')])]"/>
</record>

Create a new group and add new group for employee menu as well as remove employee group from the menu