楼上 (lóu shàng) means “upstairs” | MotiTan Chinese Dictionary

More examples

晚上，楼上还亮着灯。wǎn shàng lóu shàng hái liàng zhe dēng

In the evening, the lights upstairs are still on.

A higher level inside the same building as the reference point.

上面shàng miàn: The position on top of or above an object or place.
上边shàng biān: The upper part or area of an object or place.

在建筑物中位于某楼层之上的一层或多层的位置。zài jiàn zhù wù zhōng wèi yú mǒu lóu céng zhī shàng de yì céng huò duō céng de wèi zhì

楼 (lóu, "building with several floors") + 上 (shàng, "above") forms a word for a level located higher within that building.

The exact number of higher floors comes from context, so the word can refer to the next floor or to a group of floors above.