Here is the code
// security/user_groups.xml
<?xml version="1.0" encoding="utf-8"?>
<odoo>
<data>
<record model="ir.module.category" id="module_management">
<field name="name">Hotel Permission</field>
<field name="description">Access Security</field>
<field name="sequence">3</field>
</record>
<record id="group_admin" model="res.groups">
<field name="name">Admin</field>
<field name="implied_ids" eval="[(4, ref('base.group_user'))]"/>
<field name="users" eval="[(4, ref('base.user_root'))]"/>
<field name="category_id" ref="module_management"/>
</record>
<record id="group_user_receptionist" model="res.groups">
<field name="name">User</field>
<field name="implied_ids" eval="[(4, ref('hotel.group_admin'))]"/>
<field name="category_id" ref="module_management"/>
</record>
</data>
</odoo>
// views/hotel.xml
<?xml version='1.0' encoding='utf-8'?>
<odoo>
<data>
<!-- Add you code here -->
<!-- hotel.room tree view -->
<record id="room_view_tree" model="ir.ui.view">
<field name="name">hotel.room.view.tree</field>
<field name="model">hotel.room</field>
<field name="arch" type="xml">
<tree>
<!-- Add your fields here -->
<field name="room_number"/>
<field name="room_type"/>
<field name="room_price"/>
</tree>
</field>
</record>
<!-- hotel.room form view -->
<record id="room_view_form" model="ir.ui.view">
<field name="name">hotel.room.view.form</field>
<field name="model">hotel.room</field>
<field name="arch" type="xml">
<form string="Add Room">
<sheet>
<group>
<!-- Add your fields here -->
<field name="room_number"/>
<field name="room_type"/>
<field name="room_price"/>
</group>
</sheet>
</form>
</field>
</record>
<!-- hotel.room action window -->
<record id="room_action" model="ir.actions.act_window">
<field name="name">Room</field>
<field name="type">ir.actions.act_window</field>
<field name="res_model">hotel.room</field>
<field name="view_mode">tree,form</field>
<field name="view_type">form</field>
</record>
<!-- This Menu Item will appear in the Upper bar, that's why It needs NO parent or action -->
<menuitem id="hotel_menu_root" name="Hotel" sequence="100"/>
<!-- This Menu Item Must have a parent -->
<menuitem id="hotel_menu_categ" name="Hotel" parent="hotel_menu_root" sequence="110"/>
<!-- This Menu Item must have a parent and an action -->
<menuitem id="room_menu_act" name="Room" parent="hotel_menu_categ" action="room_action" sequence="170" groups="hotel.group_admin"/>
<!-- hotel.register tree view -->
<record id="register_view_tree" model="ir.ui.view">
<field name="name">hotel.register.view.tree</field>
<field name="model">hotel.register</field>
<field name="arch" type="xml">
<tree>
<!-- Add your fields here -->
<field name="register_number"/>
<field name="check_in"/>
<field name="check_out"/>
<field name="duration"/>
<field name="total"/>
</tree>
</field>
</record>
<!-- hotel.register form view -->
<record id="register_view_form" model="ir.ui.view">
<field name="name">hotel.register.view.form</field>
<field name="model">hotel.register</field>
<field name="arch" type="xml">
<form string="Register">
<sheet>
<group>
<!-- Add your fields here -->
<field name="register_number"/>
<field name="check_in"/>
<field name="check_out"/>
<field name="room_type"/>
<field name="duration"/>
<field name="total"/>
</group>
</sheet>
</form>
</field>
</record>
<!-- hotel.register action window -->
<record id="register_action" model="ir.actions.act_window">
<field name="name">Register</field>
<field name="type">ir.actions.act_window</field>
<field name="res_model">hotel.register</field>
<field name="view_mode">tree,form</field>
<field name="view_type">form</field>
</record>
<!-- This Menu Item must have a parent and an action -->
<menuitem id="register_menu_act" name="Register" parent="hotel_menu_categ" action="register_action" sequence="130" groups="hotel.group_user_receptionist"/>
<!-- hotel.guest tree view -->
<record id="guest_view_tree" model="ir.ui.view">
<field name="name">hotel.guest.view.tree</field>
<field name="model">hotel.guest</field>
<field name="arch" type="xml">
<tree>
<!-- Add your fields here -->
<field name="guest_id"/>
<field name="guest_name"/>
<field name="guest_sex"/>
</tree>
</field>
</record>
<!-- hotel.guest form view -->
<record id="guest_view_form" model="ir.ui.view">
<field name="name">hotel.guest.view.form</field>
<field name="model">hotel.guest</field>
<field name="arch" type="xml">
<form string="Guest">
<sheet>
<group>
<!-- Add your fields here -->
<field name="guest_id"/>
<field name="guest_name"/>
<field name="guest_sex"/>
</group>
</sheet>
</form>
</field>
</record>
<!-- hotel.guest action window -->
<record id="guest_action" model="ir.actions.act_window">
<field name="name">Guest</field>
<field name="type">ir.actions.act_window</field>
<field name="res_model">hotel.guest</field>
<field name="view_mode">tree,form</field>
<field name="view_type">form</field>
</record>
<!-- This Menu Item must have a parent and an action -->
<menuitem id="guest_menu_act" name="Guest" parent="hotel_menu_categ" action="guest_action" sequence="150" groups="hotel.group_admin/>
</data>
</odoo>