Kidney disease often ends up being a multi-disciplinary thing. A nephrologist is not the only person you need to consult. With long term kidney disease, there are some conditions that could need you to consult a cardiologist, a neurologist, a hepatologist, an orthopedician, a dermatologist, a urologist and a vascular surgeon among others!
Most of these referrals will be by your primary nephrologist. Now there are often two choices in front of a nephrologist. He could either refer you to someone from the hospital you see him in or where he primarily works or he could refer you to who he thinks is the best (or at least very good) in the city.
Both these approaches have their pros and cons.
Referring you to the best in the city may be good because obviously you are seeing someone who is likely to advise the best course of treatment. However, as is almost always likely, there will be a need to consult the nephrologist because these kinds of things are not always black and white. In these cases, it could be better for both to be a part of the same team, in the same hospital. Things becomes much easier to discuss.
I see my nephrologist mostly at his clinic and rarely at his primary hospital. He inevitably refers me to the best in the city or to someone he thinks is very capable. He initially leaves the choice to me. And I invariably ask him to recommend someone.
As a result, I now see specialists in about five hospitals in the city! This might, at some point, becomes a logistical nightmare as it will be impossible to get these doctors to come together to discuss anything!