北京第五家山姆门店在昌平开业，山姆全国门店数达61家

Group 1 - The core point of the article is the opening of the Sam's Club store in Changping, Beijing, marking the company's continued expansion in China [1] - Since 2003, Sam's Club has opened a total of 5 stores in Beijing, with the Changping store being the 61st store nationwide [1]