This is the present perfect subjunctive to convey moods, desires of what has already happened.

I'm sad that you have been sick.

The doctor doubts that you have had pneumonia.

To form take subjunctive of haber + past participle

I'm sad that you have been sick.

Siento que hayas estado enfermo.

El doctor duda que haya tenido pulmonía.

El color negro más brillante que Usted jamás haya visto.

The color black more brilliante than you have ever seen.