在…上 / 在…中【zài…shàng / zài…zhōng】

在 + noun + 上 and 在 + noun + 中 use the words for "on" and "in" with things that aren't places. 上 marks an area or an issue: "in terms of", "on the matter of". 中 marks something you're inside of – a process, an activity, a group.

在…上: an area or an issue

The noun is usually abstract: 学习, 工作, 生活, 时间, 态度, or a specific question. 在这个问题上 means "on this issue".

在…方面 covers the same ground and is a little more formal; 在…上 is the everyday choice.

在…中: inside a process or a group

中 goes after an activity that takes time, or after a group, a story or a situation. 在…过程中 "in the course of" is the set form.

里 is for places

English "in my studies" or "in this question" invites 里, but 里 is for physical insides. An abstract area takes 上 or 中.

• × 在学习里，他很努力 → 在学习上，他很努力
• × 在这个问题里，我同意你 → 在这个问题上，我同意你

在…下, "under" a condition (在老师的帮助下), has its own point.