It is a term used in certain areas, like Jungians call what they do depth work. And sometimes it does involve analysis of the unconscious material if that is part of the orientation and process of the therapy.

For me, though I don't actively use the term, I do implicitly use the concept all the time. After crisis issues or things about stressors and dysregulation, the things taken on in therapy have been deeper issues that usually involve trauma and early developmental derailments. I have found that even in adult trauma, there is a strong connection to something early in life that has affected how I have reacted to the trauma. Going back to what amounts to different ways my character or self was formed and actually making changes at that level are transformative. I would consider that to be depth work.