Some American Basketball players can get a second passport because their parents (or sometimes grandparents) have different nationalities.
Potential benefits of dual basketball nationality
American players who have dual basketball nationality can get either the “Cotonou status,” the “Domestic status,” or the “Bosman status.”
Most professional leagues overseas have an import quota, meaning a maximum number of foreign players per team is allowed. Having dual nationality is a way to work around that.
If a player, for example, has American nationality AND that of the Philippines, he can play in that country as a domestic player. This boosts his chances and sometimes makes him eligible to play for that country’s national team. 
If a player has a passport from a European country, then in addition to the status of the domestic player, he also gets the “Bosman status.” This means that in most other European countries, he will have a higher status than a regular import. More “Bosman players” are generally allowed in a league than true import players. In other words, a passport from a European country gives a player two advantages—that of the country itself plus that of other European countries.
A Cotonou status is given to players from most African and Caribbean countries. It is similar to the “Bosman status,” but few countries have this rule. In some countries from the Middle East, an African passport could be an advantage.
Is it worth the hassle?
It may seem like a dual basketball nationality has many advantages, but it is not always true.
A passport alone is not enough. Like always, a player must have a solid resume, and in international Basketball, that often means having impressive stats at a good level. Otherwise, dual basketball nationality doesn’t mean much. On the other hand, when two excellent players with equally impressive resumes are competing for the same job, the one with a dual basketball nationality might have an advantage.
Elite players who may be good enough to qualify for the national team should definitively consider dual nationality.
All other players need to understand that a good resume gets them jobs. Not a foreign passport.
In addition, getting dual basketball nationality can sometimes be a complicated and lengthy process that could take years, and every player has to ask himself if t is really worth it. Since more and more leagues worldwide are getting rid of the restrictions for import players, it doesn’t matter who has which nationality anymore.