I had left ing hernia surgery 3 months ago and hematoma about the size of a golf ball is still present in my scrotum. Does this require more surgery?

Generally No. Assuming the diagnosis is correct, post-op scrotal hematomas usually always resolve completely or become much smaller with time over a period of many months. Surgical excision is rarely needed unless the hematoma becomes infected or is associated with persistent, bothersome discomfort after an adequate period of observation which is uncommon.
I do not. Think so. The hematoma after three month is organized. Yet, why don't you go back the the surgeon, show him the scrotum and ask what is his opinion. If there is fluctuation felt, maybe a simple aspiration will be enough to reduce size.
Unlikely (NO) Hematoma will get absorbed in couple of months, no evacuation is required. Speak to your surgeon for assurance.