I doubt that there is an English version. At least I cannot find one.Here is the Japanese version:
http://www.chugoku-jrbus.co.jp/annai_rosen/pdf_yamaguti/03-jikoku_b.pd...
The Yamaguchi-Hagi timetables are the two tables in the lower row.
新山口駅新幹線口 refers to Shin-Yamaguchi Station (Shinkansen Exit)
山口駅 refers to Yamaguchi Station
東萩駅 refers to Higashi-Hagi Station
※ means that the bus does not operate on weekends
◆ means the the bus operates only on weekends