“Wheels within wheels”= famous expression from the Bible (Ezekiel 1:16)

“Wheels within wheels” means a situation that is complicated due to secret or indirect influences.

It comes from a vision in Ezekiel 1:16: “The appearance of the wheels and their craftsmanship was like the gleam of beryl, and all four had the same form. Their appearance and craftsmanship was like a wheel within a wheel.”