In your City Model add

public function region()
{
    return $this->belongsTo('App\Region');
}

You can access the region like

User::with('city.region')->get();

I was abble to fix it with the help of one friend.

Finally I'm getting the data from one user, in my controller using something like:

$user = \DB::table('user') ->select( 'user.id', 'user.name', 'city.name as city_name', 'region.name as region_name') ->leftJoin('city', 'user.city_id', '=', 'city.id') ->leftJoin('region', 'city.region_id', '=', 'region.id') ->where('operator.id', '=', $id)->first();

Thanks for try to help me.

model user
----------
...
// add this
public function city_master()
{
    return $this->belongsTo('App\City', 'city_id');
}
...


model city
----------
...
// add this
public function user_master()
{
    return $this->hasMany('App\User', 'city_id');
}

public function region_master()
{
    return $this->belongsTo('App\Region', 'region_id');
}
...


model region
------------
...
// add this
...
public function city_master()
{
    return $this->hasMany('App\City', 'region_id');
}

so you can call all relationship data

// for user

$model = User::get();

foreach ( $model as $key => $value ) {
    print_r( $value->city_master )
    print_r( $value->city_master->region_master )
}


// for city

$model = City::get();

foreach ( $model as $key => $value ) {
    print_r( $value->region_master )
    print_r( $value->user_master )
}


// for region

$model = Region::get();

foreach ( $model as $key => $value ) {
    print_r( $value->city_master )
    print_r( $value->city_master->user_master )
}