A complex capital structure is a construct where companies offer multiple forms of securities, rather than solely offering a single class of common stock.

Bectran Unveils Support for Complex Account Hierarchy Structure to Provide Optimal Credit Risk Aggregation. September 22, 2022 11:00 AM Eastern Daylight Time. CHICAGO-- ...

Corporate hierarchy refers to the arrangement of ... a hierarchy is any system or organization in which people or groups ... while the structure of larger corporations tends to be more complex.