What is this filibuster you speak of?
They are allowed to delay a nomination for a few days by forcing the Republicans to move to end debate. That motion can be heard a few days after it is made, I think 3. So, they can speak for a few days, then when the motion is made, delay it a little longer. That was done with Kavanaugh. The difference between rules now and before Harry Reid changed them is that it now only takes a majority to end debate, not 60 votes.