Just like the UN, but inclusive of non-countries: corporations, individuals, etc.
The United Nations is not representative of the modern diverse world, of individuals, companies, organizations, and countries, considering only countries as worthy participants in deciding about the issues of global matters.
However, the top-down hierarchical structure without inter-level connections (like semi-lattices, common in natural brains), may be not the best or most representative of actual humanity's goals.
For example, today corporations, individuals and other type of entities are important to deciding about the global goals, but not directly included.
The "United Entities" would be an inclusive organization for global governance, open to everyone, from countries to corporations, to individuals, where every entity can participate on equal footing in decision-making, based on certain "entity rights and responsibilities" of participation, that would have to be defined.
(This may even be financially viable, as corporations of today sometimes exceed even countries in their capabilities, and do represent the world's efforts towards specific domains of endeavor that matter, and that they are the best equipped to address, so why not to talk and vote on global policies on those issues directly, rather than lobbying politicians.)