fig. shortcut to a high-flying career; easy route to success (an allusion to the Tang Dynasty story of 盧藏用|卢藏用[Lu2 Cang4 yong4], who lived like a hermit on Mt. Zhongnan in order to gain a reputation for wisdom, which he then used to gain a position in the Imperial Court)
Definitions (Wiktionary)
phrase, idiomatic
the shortcut to be an official, etc.