Show only one record in Mult-Tenant auth System Laravel

I’m building a mult-tenant auth system, that each user can belong of “x” companies. In Users Table, there is a field named “companies_id”, that contain the companies IDS that he belongs ( between “,” ), ex: 1,9,25,30. I can List all User Companies through query scopes e Query Builder:

class Company extends Model
{

    protected static function boot()
    {
        parent::boot();

        static::addGlobalScope(new CompanyScope());

}

class CompanyScope implements Scope
{

    public function apply(Builder $builder, Model $model)
    {

$companies_id = auth()->user()->companies_id;
    $pieces = explode(",", $ companies _id);
    foreach ($pieces as $k){
        $builder->orwhere('companies_id', $k);
}
}

In INDEX page is OK, but, if I need show only ONE Company that a user belongs I can’t. I Have a Method in Company Controller : Show($id){ }.

via Chebli Mohamed