Try changing:

class MenusController extends \BaseController {

to

class MenusController extends Controller {

Unless I'm missing something.

Nope that didn't work

You're mixing singular/plural in your models. If a Menu can have one parent, tell it that and name it as such, if a Parent can have many Menus, then name it and make it as such.

Right now you have a Menus model which should be named Menu, then in Parent you name the function menus, but tell the relation you expect it to have one menu. Do not mix plural/singular and make sure everything matches the name of your model to work smoothly.

public function parent(){ //->relationship name, important
        return $this->hasMany('Parents'); //->model name, not important
    }

If you want to eager load it then use

::with('parent')->...

I'm trying to save parent into the menus table. Parent references the id of the menu.

Isn't

::with('parent')->

a way to display menus with a parent?

Your problem was eager loading non-existing relation (with('Parents')).

Also I'm retty sure an entry doesn't hasMany parents, but rather belongsTo a single parent.