Create Module Structure

Enter Module Name and Zip File Name

Module Name : It will be name of the app
Zip File Name : It will be name of the zip file which contains app

Configure Manifest File Structure

Sequence : Must be 1 to display your app at top of the list in app list
Installable : Must be true, to install an app
Application : If true, app will display in apps which is default filter when we click on Apps in Odoo
Auto Install : If true, app will automatically install when the database is created

Specify Name of the Menus

Now, Create Model
Once top and sub-menus are created now its time to create actual menu which displays our custom fields
And for that we need to create model also to store custom fields

Enter Menu Name and Model Name

Now, add Custom Fields to that Model

Create Field

Employee is Many2one Field so add Related Model for that

Same this you can create Many2many also

Other Configuration of a Field

Show in Tree : If true, it will show field into tree view also, in form view its default
Required : If true, fields value can't be empty
Index : If true, it will create index of a field into database - used for searching purpose
Copy : If true, field's value will be copied while duplicating record

Create another field
You can create as much as fields which you want

Other Optional Configuration into Model

Description : Simple description for your model
Order : Used for sorting records into tree view based on field, default order will be ascending
Descending Order : If true, record sorting will be into descending order

Next, add this Model to Module Structure

Module Structure: add Readme, Contributors if needed

Finally, click here to Generate App

Now, download app from here

Install App

Installed, Menus are set as Configured

Custom Fields : Form View

Custom Fields : Tree View