I'm not an expert in the Pathfinder world geography (or our world, if I'm honest).
Mwangi Expanse seems to be sub-Saharan Africa. Their equivalent of North Africa seems to be an area called the Golden Road, consisting of the nations of Katapesh, Osirion, Qadira, Rahadoum, and Thuvia. That is beyond the Barrier Wall, which is considered the northern border of the Mwangi Expanse. The Golden Road area has about 11 pages of content in the Lost Omens World Guide, which is basically an overview of the campaign setting.