Number + 层
层 (céng) is a noun meaning "layer," "level," or "floor." It is used to describe stacked or hierarchical structures, whether physical like building floors or abstract like cortical layers. For example, 第三层 means "the third floor."
这栋楼一共有二十层。
Zhè dòng lóu yīgòng yǒu èrshí céng.
This building has twenty floors in total.
蛋糕有三层,每层口味不同。
Dàngāo yǒu sān céng, měi céng kǒuwèi bùtóng.
The cake has three layers, each with a different flavor.
我们需要从多个层面来分析这个问题。
Wǒmen xūyào cóng duō gè céngmiàn lái fēnxī zhège wèntí.
We need to analyze this problem from multiple levels.