山場平處 Which One Is Your Chief
這大聖與八戒急退幾步，到那山場平處，抵住群妖，喝道：「那個是出名的頭兒？那個是拿我師父的妖怪？」这大圣与八戒急退几步，到那山场平处，抵住群妖，喝道：「那个是出名的头儿？那个是拿我师父的妖怪？」
逐句解 Line by line
The Great Sage and Bajie fell back a few quick paces to a level place on the mountain clearing, held the pack of fiends off, and shouted, "Which of you is the chief they all talk about?
Falling back to level ground is a real tactical choice and the novel treats it as one. 山場 is a clearing on a hillside — a genuine place, so 場 keeps the ordinary chǎng here, and the same character will take a different reading a few passages on where it counts a bout of fighting instead. 那 is nǎ, which — a question, not a pointing word.
Which is the fiend that took my master?"
The second 那 is nǎ as well. Wukong asks two questions and they are not the same question: who is in charge, and who did it. He is expecting two different answers and he will get one creature claiming both.
Wukong's two questions are a piece of professional practice. Identify the commander, identify the culprit, and if they are the same creature the fight is simple. He has done this in dozens of chapters and it usually works.
The retreat to level ground is worth a moment. Wukong could fight anywhere. Bajie could not, and Wukong is picking the terrain for his brother without saying so.