How can I add a button in a view that opens another (full screen) view of my choice?

Have a look at tutorial 6:

It explains hohttps://www.vigo6.com/tutorial-6-adding-views-main-view/w to add either standard buttons  or custom made buttons

NB! The view always opens in its built-in size. It means, there is no “show on full screen”-mode. But as long as you design your view for your maximum screen size you will get the effect you want.