Let's take a trust and company ownership as an example. You own a business and it's doing well, but for whatever reason, you want to no longer be the UBO but you also don't want to sell it outright.
You go to a trustee and draft up a trust deed, whereby you as the Settlor settle the company (or at least your shares of the company) in a trust, which is managed by the Trustee. You might︀ appoint your cousin, best friend, or long-time trusted attorney as Protector of the trust. The︁ Protector's role is to ensure that the trustee does with the entrusted assets what was︂ laid out in the deed. In the trust deed, you can stipulate further control mechanisms︃ to ensure that the trustee doesn't just liquidate the company and run with the money.︄ You can for example mandate that other people you trust hold senior positions or directorship︅ roles within the company.
You no longer own the company and will become irrelevant for︆ reporting purposes, if the whole structure is set up correctly.
Now, the OECD and its︇ ilk aren't stupid. They know about these arrangements and have worked mechanisms into the AEOI/CRS︈ protocol to ensure this isn't exactly as easy as described above. For example, when the︉ company then goes to open a bank account, the Settlor's identity needs to be disclosed︊ (SOF/SOW checks on the trust). To avoid also that, you need to take extra steps,︋ which are tailored to your specific situation, hence the need to work out custom arrangement︌ each time. But that's kind of the gist of it.
Above is a massive oversimplification.︍ I can't stress enough that these arrangements need to be thought out in detail by︎ qualified people. It frustrates me to see certain CSPs selling trusts and foundations for a️ few thousand, because it gives people the impression that would somehow work. In reality, these setups almost always include several layers and chains of trusts and foundations, Anstalt, Stiftung, SPIC, and all sorts of other arrangements and entities that creative lawyers all over the world have helped write into law.
One of the hardest parts tends to be the return of assets to the Settlor in a way which does not fracture the integrity of the initial trust.
