Focal segmental glomerulosclerosis (FSGS) is a chronic scarring disease of the kidney and has five different pathological classifications including “tip lesion or variant”. You are correct that there is no universally recognized treatment for FSGS. The most common treatment is to use ACE-inhibitors or ARB agents with diuretics as needed. Prednisone (steroids) are commonly used to test the response. If someone responds to steroids, this is a good prognostic sign. If no response, then prognosis is not as good.
Neither I nor the National Kidney Foundation provide referrals for care.