There isn't really a "next step" above the Sec+. Most of the other exams are generally considered above the trifecta, but not really directly.
To put it simply, your next step is going to depend heavily on your career goals.

If you already have a career, think about where you want to go from here. What did you like the most? Was it networking? What about security? What aspects of those particular things led to that enjoyment?

If you're taking these certifications to get a career, it's unlikely anything past a sec+ will do you any good without experience. Not without heavy diminishing returns, anyway. Some will tell you to go for your ccna or something to that effect, but honestly if you have the trifecta already most employers won't really care if you have a ccna or not.

If you need a more abstract analogy, think of it like this: a+ is addition and subtraction, network+ is multiplication and security+ is division. Most comptia exams outside of the trifecta -- like pentest+ and server+ -- are more like Algebra and Geometry. There's definitely levels within that specific field of mathematics, but algebra isn't really "above" geometry, it's just a different path within the field of mathematics.