Relationship between Permalink and Categories

Let's assume there's a category Business and sub-category News and Interviews

and there's another category Region with sub-categories as Europe, Americas, Asia

and for a post the categories selected was Business and New and Region and Europe

What will the permalink be if the format is https://site-name/category/post-name/?

I've been getting random permalinks and can't seem to figure out a method of understanding the method.. Could you please suggest how do I choose which category gets displayed in the permalink if I have multiple categories?

Also is there an option to ensure that some categories exist but would never appear in the permalink? If yes, could you please suggest how I could achieve this