I think the dimension known as "Hell" from Agents of SHIELD Season 4 is actually the Dark/Darkforce Dimension.
First, "Hell" is not necessarily the official name for this dimension. Robbie Reyes says the term is "relative".
The Ghost Rider plot features several references to the "Zero Matter" plot from Agent Carter Season 2, with mentions to Isodyne, Roxxon, and Darkforce.
The book Darkhold was made of "dark matter" from the Hell dimension. "Dark matter" sounds like "Zero Matter/Darkforce".
Robbie Reyes took the Darkhold back to the "Hell", and later Morgan le Fay from the "Dark Dimension" owns the book. It makes sense for it to be the same place.
Just theories and speculations.
