I am not aware of a "Berry Brock Plantation" in Campbell Co.
There was a Berry Brock b. 1894 who was the s/o Augustus Lafayette Brock, the youngest son of Henry Brock (b. 1802 in SC). Henry Brock owned several hundred acres of land in Campbell Co. and, according to tax and census records, owned as many as 4 slaves at one time. Berry Brock had a son, Berry, Jr., who still lives in South Fulton Co. on land once owned by Henry.
Aside from those two men, I know of no other Berry Brock's. It sounds like your Swanns may have been living on land owned by Berry Brock, Sr. which they called the Berry Brock Plantation.
What other info do you have? How old are the relatives who are giving you your info? What dates were they living on the BB Plantation?