Hi Erhuvwu, you don't need to do anything in the backend, just follow these steps in the webclient:

1.Create a new group,

select Setting>>Users>>Groups, click 'create',

entering the Name field(e.g. New Group),

in the Users tab, add Users,

in the Views tab, add Views,

in the Access Rights tab, add objects;

2.Create a Top Menu,

select Settings>>Technical>>Interface>>Menu Items, click 'create',

entering the Menu field(e.g. New Top Menu),

in the Groups tab, add Groups(e.g. New Group);

3.Create Main Menus(e.g. New Main Menu) under Top Menu,

select Settings>>Technical>>Interface>>Menu Items, click 'create',

entering the Menu field(e.g. New Main Menu),

choose Parent Menu(e.g. New Top Menu);

4.Create Menus(e.g. Customers) under New Main Menu,

select Settings>>Technical>>Interface>>Menu Items, click 'create',

entering the Menu field (e.g. Customers),

choose Parent Menu(e.g. New Main Menu),

choose action(e.g. ir.actions.act_window => Customers).

(Done)

This will helpful: