autocde2.0/app/Http/Requests/RuleHelper.php

<?php

namespace App\Http\Requests;

use App\Models\User;
use Illuminate\Database\Query\Builder;
use Illuminate\Support\Facades\Auth;

trait RuleHelper
{
    protected function userCompanyWhere(): \Closure
    {
        return fn (Builder $query) => $query->where('company_id', Auth::user()->company_id);
    }

    protected function usersCompanyRules(): array
    {
        return [
            'array',
            function ($attribute, $value, $fail) {
                $userCount = User::where("company_id", Auth::user()->company_id)->whereIn('id', $value)->count();
                if ($userCount != count($value)) {
                    $fail('The selected user is invalid.');
                }
            }
        ];
    }
}