How Are Aliens Treated in Domestic Courts?

From a post at the EFILA blog:

An investor in a Host State court is automatically an alien, advancing a claim in a foreign court automatically places the investor at a disadvantage of itself.

This seems like an assertion that could be studied empirically. How are aliens treated in domestic court, as compared to how citizens are treated there? And within the category of aliens, how are foreign investors treated as compared to, say, indigent farmworkers?