David Pierson, Lynsey Chutel, Jack Nicas, Alex Travelli and Paul Sonne

The group of nations known as BRICS — Brazil, Russia, India, China and South Africa — represents 40 percent of the world’s population and a quarter of the world’s economy. Now it is considering expanding, in a push to be seen as a credible counterweight to Western-led forums like the G7 group of…