Citation, Documentation of Sources

Q. How should I index the name Teodoro Obiang Nguema Mbasogo?

A. In the absence of other information or advice (such as from the author), index unfamiliar unhyphenated names in the usual way, under the last name listed—in this case, Mbasogo. CMOS 16.71–74 and 16.75–87 cover rules for indexing special types of personal names.

[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]