I visited San Diego Zoo last week, the mammal mixed species exhibits for these two complexes were:
Ituri Forest:
Larger enclosure had Western forest hog, red river hog, forest buffalo, and Allens swamp monkey.
Smaller enclosure also had Allens swamp monkey, and Schmidts spot-nosed guenon and African spot-necked otter.
MonkeyTrails and Forest Tales:
Eastern Angolan colobus and black mangabey.
Mandrill, colobus, and Schmidts spot-nosed guenon.
Wolf's guenon and pygmy hippopotamus.
Other mammal mixed species exhibits at the zoo:
Absolutely Apes:
Orangutan and siamang.
Urban Jungle (former Elephant Mesa):
Giraffe and Soemmerings gazelle.
Outback (near koalas):
Red ruffed lemur and rock hyrax.
Kopje:
Klipspringer, rock hyrax, and dwarf mongoose (I did not see mongoose but the sign is certainly still there).
Polar Rim (former Horn and Hoof Mesa section that was not demolished for Elephant Odyssey):
Lesser kudu, Cavendishs dik-dik, red-flanked duiker, Spekes gazelle.
Gerenuk and more Cavendishs dik-dik.
Steenbok and more red-flanked duiker.
Elephant Odyssey:
Bairds tapir, guanaco, and capybara.
Dromedary camel, alpaca, horse, burro. (Domestics in a yard with occasional supervised contact area).