“Celtics/Lakers: Best of Enemies,” a five-hour 30 for 30 film event, chronicles the storied franchises’ epic clashes and relives the Boston-LA battle from both sides, with sensational footage and fresh, insightful interviews. The three-part documentary will premiere with Parts One and Two back-to-back on Tuesday, June 13, at 8 p.m. ET on ESPN and Part Three on Wednesday, June 14, at 8 p.m. ET on ESPN.