proceed from the exterior to the interior (/from the outside to the inside/from the surface to what lies behind/from outward appearance to inner essence)
❍ 分析问题，要～。The analysis of problems should be proceeded from the surface to what lies behind.
由表及里yóu biǎo jí lǐ
从外到里，由表面现象到本质内容。proceed from the outside to the inside, from the outside to the inside, through the out into the inside