精于此道

to be proficient in the area of / skilled in this field

essence / extract / vitality / energy / semen / sperm / mythical goblin spirit / highly perfected / elite / the pick of sth / proficient (refined ability) / extremely (fine) / selected rice (archaic)

skillful in / proficient in / adept at

to go / to take / sentence-final interrogative particle / variant of 於|于[yu2]

(of time or place) in; at; on / (indicating any indirect relation) to; toward; vis-à-vis; with regard to; for / (indicating a source) from; out of / (used in comparison) than / (used in the passive voice) by

this / these

this; these

such matters / things like this / this line of work / this pursuit / this hobby / this endeavor

road / path / CL:條|条[tiao2],股[gu3] / principle / truth / morality / reason / skill / method / Dao (of Daoism) / to say / to speak / to talk / classifier for long thin things (rivers, cracks etc), barriers (walls, doors etc), questions (in an exam etc), commands, courses in a meal, steps in a process / (old) circuit (administrative division)