ldc-dam/app/Scopes/SystemScope.php

<?php

namespace App\Scopes;

use Illuminate\Database\Eloquent\Scope;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Builder;

class SystemScope implements Scope
{
    /**
     * Apply the scope to a given Eloquent query builder.
     *
     * @param  \Illuminate\Database\Eloquent\Builder $builder
     * @param  \Illuminate\Database\Eloquent\Model   $model
     * @return void
     */
    public function apply(Builder $builder, Model $model)
    {
        $builder->where('system', false);
    }
}