BRICS is going after two things and it's becoming increasingly transparent: natural resources and shipping lanes. Expect Indonesia (Malacca) and Algeria (Alboran Sea) to come soon.

If BRICS continues to expand towards natural resources, expect Kazakhstan and Bolivia. If BRICS continues to expand towards human capital, expect Bangladesh, Pakistan, Vietnam, and Thailand.

The world can be separated into a few cultural superblocs: Europe, the colonial West (North America, Australia, etc.), Indigenous/Latin America, the Arab World, sub-Saharan Africa, Hannafi Islam (including Turkey and Pakistan), Southeast Asia, and the blocs defined around Russia, China, and Iran.

There's an increasing degree of separation between the first two blocs (Europe and the colonial West) and the rest, and BRICS has made significant progress towards unifying these remaining blocs:

In Latin America, there is Brazil (ex-Argentina).

In the Arab World, there is Saudi Arabia, the UAE, and Egypt.

In sub-Saharan Africa, there is Ethiopia and South Africa.

There's a distinct lack of expansion towards the bloc represented by Hannafi Islam, but this is largely because this bloc is geopolitically dependent on the 4 BRICS countries surrounding it (Russia, China, India, Iran).

Then there is Southeast Asia, which has rather poor representation in BRICS and which MUST be corrected if BRICS seeks to unify the Global South.