I have a situation which will help us to understand the use of Global Filtering.

Situation:

I have a published filter that I use for my articles. Guests can only view published articles, logged in users can view and apply filter (?published=0/1):

To solve this problem we will follow the two step:

1) Create a class PublishedScope that implements ScopeInterface

class PublishedScope implements ScopeInterface {

public function apply(Builder $builder)
{
    $table = $builder->getModel()->getTable();
    $builder->where($table.'.published', '=', 1);
    $this->addWithDrafts($builder);
}

public function remove(Builder $builder)
{
    $query = $builder->getQuery();
    $column = $builder->getModel()->getTable().'.published';
    $bindingKey = 0;
    foreach ((array) $query->wheres as $key => $where)
    {
        if ($this->isPublishedConstraint($where, $column))
        {
            unset($query->wheres[$key]);
            $query->wheres = array_values($query->wheres);
            $this->removeBinding($query, $bindingKey);
        }

        // Check if where is either NULL or NOT NULL type,
        // if that's the case, don't increment the key
        // since there is no binding for these types
        if ( ! in_array($where['type'], ['Null', 'NotNull'])) $bindingKey++;
    }
}

protected function removeBinding(Builder $query, $key)
{
    $bindings = $query->getRawBindings()['where'];
    unset($bindings[$key]);
    $query->setBindings($bindings);
}

protected function addWithDrafts(Builder $builder)
{
    $builder->macro('withDrafts', function(Builder $builder)
    {
        $this->remove($builder);
        return $builder;
    });
}

2 Boot that class in your Eloquent model by calling static::addGlobalScope(new AbcScope)

// the model
public static function boot()
{
    parent::boot();

    static::addGlobalScope(new PublishedScope);
}

If I were you I would use published_at column and check it for null instead of = 1, but that's up to you.

By this we can solve this issue.