BEM how to organize nesting of VIEW and controllers?

Question

JavaScript

Good afternoon! I'm trying to try on BEM for the current moment. I do not quite understand how it works and at what level data processing takes place. There is a bekovsky controller which works with models. Where should he send the data? In theory, I also need a front controller.
For example, I need to display a view whose parts are implemented by other views. Where can I determine exactly which parts of the main view I need to include?
How does nesting of different views work inside BEM? And if I need to get additional data in these small views, where can I define it?