如何创建Laravel多态关系，其中每种类型具有不同的多重性级别

Question

Ok, so I'm trying to create a polymorphic relationship in Laravel that has four different types. The problem I have is that two of those levels are one-to-many and the other two are many-to-many. Here's what I have so far:

class Holiday extends AbstractModel {
  protected $table = 'holidays';

  protected $fillable = [
  'scope_id', 'scope_type', 'main_date', 'alt_date', 'comp_date', 'name', 'disabled'
  ];  

  public function scope() {
    return $this->morphTo();
  }
}

class Country extends AbstractModel {
  protected $table = 'countries';

  protected $fillable = ['name', 'iso_code', 'disabled'];

  public function holidays() {
    return $this->morphMany("App\holidays", "scope");
  }
}

class CountrySubdivision extends AbstractModel {
  protected $table = 'countries_subdivisions';

  protected $fillable = ['name', 'iso_code', 'countries_id', 'disabled'];  

  public function holidays() {
    return $this->morphMany("App\holidays", "scope");
  }
}

This is good for the first two levels which are one-to-many relationships. However, my problem lies in the last two levels which are many-to-many. Here are my models:

class Site extends AbstractModel {

  protected $fillable = ['name', 'code', 'division', 'absence', 'unpaid'];

  public function holidays() {
    return $this->morphToMany("App\Holiday", "scope");
  }
}

class Employee extends AbstractModel {

  protected $fillable = [
    'name', 'code', 'division', 'absence', 'unpaid'
  ];

  public function holidays() {
    return $this->morphToMany("App\Holiday", "scope");
  }
}

The problem I have is when defining the inverse of the relationship. the morphTo method is used for one-to-many relationship. However, for many-to-many, I need to use the morphedByMany() method. however, I don't know how to use two different qualifiers for the same relationship.

Anyone know how to do this?