Hi, I'm Krueger, I'm an old sysadmin in TOR, my stay at the Deep Web is broad enough to explain how it works and what it is.
The Deep Web is not based on levels, they are simply networks with infrastructures that we know as normal users, the Deep Web does not work with levels, you simply need routing software, use VPN, use proxy or tools created by the same developers of the NETWORKS.
The Deep Web is not an Ice berg in which you must go deeper to find stronger material, what you are looking for is even in ClearNet.
The legends about Marianas Web and strange domains similar to .onion are false, you can see my website if you like to find more detail about that.
Going back to the topic The Deep Web is for people who want something beyond being anonymous that is privacy, doing things without the ISP watching us, and not exactly illegal things that many people also misuse that but the goal of being Anonymity to a certain extent and having privacy is quite clear on the Deep Web in any of the Networks.