上个
shàng​ge

previous; the above

上个 上個 shàng​ge
previous; the above determiner
The one before; last (week, month, etc.); the aforementioned

上个周一我去钓鱼了。

shàng​ge zhōu​yī wǒ qù diào yú le.

I went fishing last Monday.

向上再向左可切换到上个对话。

xiàng​shàng zài xiàng zuǒ kě qiē​huàn dào shàng​ge duì​huà.

Drag up and then to the left to switch to the previous conversation.

first part
The first of two parts, specifically in the context of volumes or sections of a book or series