misleading results from "Find Usage"

I just started using PyCharm and I'm cautiously optimistic about this program. However I did see something that worries me. It seems that "Find Usage" sometimes follows a variable through a function, but not always.

Here is my example... this is kind of hard to explain especially since the formatting options here are not great, but here you go.

Method is called here:

myobject.my_object_method(myvar='myvar_value')

later...

def my_object_method (self, myvar):

    ...

    self.another_function(myvar)

then later...

def another_function(self, myvar)

    print(myvar)

If I "find usage" on myvar at the very beginning, it will find myvar within my_object_method but not within another_function. So is there a limit to how "deep" the usage it finds will go?