Thank you for the corrections, I am sorry for being so late to respond, as I have fallen ill. This is a little complicated for me to talk about in Japanese so I hope you will excuse me for using English for a bit.

I appreciate you explaining the use of romanji when it comes to technical terms like this. I wanted to talk about the cpap in particular to see what the correct way to speak about it was, as when I travel to japan I will need to bring it with me and know how to talk about it enough to let people know its essential medical equipment.

Regarding the confusion in directions in the use of the 'の' particle, I think my confusion has less to do with the direction and more understanding what the particle is doing. Here are my example sentences I made for myself to try to get my head around the concept:

手紙は机の上の鉛筆と本の間ありにます
The letter is on the desk between the pencil and the book
自転車は公園の中のスーパーと図書館のうしろにありますか
Are there bicycles in the park behind the supermarket and library?
旅行のバス は レストラン のまえのデパートと銀行隣にありませんですた。
There was no travel bus next to the department store and bank in front of the restaurant.

The problem was I was treating の just like an apostrophe in English leading me to read this sentence:
手紙は机の上の鉛筆と本の間にあります
Like this:
手紙は[机の上の鉛筆と本の間]にあります
When I should have been reading it like this:
手紙は[机の上]の[鉛筆と本の間]にあります

DnD and all tabletop RPGS are very fun and I hope you get a chance to play one! I will try to write about playing a little in Japanese at some point.

★> 手紙は机の上の鉛筆と本の間にあります
a1> 手紙は[机の上の鉛筆と本の間]にあります
b1> 手紙は[机の上]の[鉛筆と本の間]にあります

There's also some Japanese(language)'s problem, I think.
With a1["手紙は机の上の鉛筆と本の間にあります"], I can only guess what the sentence means, with/from the shapes of 机, 鉛筆 and 本, honestly.

b1-x> 手紙は、机の上の、鉛筆と本の間にあります
｜◆ 手紙は
｜　　┗ 机の上の
｜　　　　┗ 鉛筆と 本の 間に あります

Sometimes, 読点《とうてん》, the mark of [ 、], would work to show some clearer, but Japanese phrases are easy to get ambiguous, actually.


«　手紙は　机の　上の　鉛筆と　本の　間に　あります　»
（ the letter は ｜ the desk の ｜ the top の ｜ the pencil(s) と ｜ the book(s) の ｜ the space に ｜ is《to be | あります》 ）
　　↑↓
◆ 「手紙」は、…
　　　｜　　　┏on "机"
　　　｜　　┣on "上"
　　　｜　┣on "鉛筆と本"
　　　｜　 ↓
　　　｜at 間
　　あります
”の" shows relationships like a hyperlink, I feel.

However, you cannot be sure which relates to which firmly because every part is not related to each other firmly.

Also I cannot be firmly sure …
> 「机の上の、鉛筆と本」 or 「机の上の鉛筆と、本」
>　「{鉛筆と本}の間」 or 「｛本｝の間」
… in a grammatical manner, to be honest. 😓

I'll try to translate "Are there bicycles in the park behind the supermarket and library?" into Japanese.

> 「スーパーや図書館の裏にある公園に、自転車はありますか？」

・Are there bicycles(?)　：　自転車はありますか（？）
・in the park　：　（あの）公園に
・behind [the supermarket and library]　：　（あの）スーパー と（あの）図書館 の裏に

１） Are there bicycles in the park? ： あの公園に自転車はありますか？
２） Are there bicycles in the park behind the supermarket?　：スーパーの裏の公園に自転車はありますか？
== Are there bicycles in the park, that is behind the supermarket. ： スーパーの裏にある公園に自転車はありますか？
３）Are there bicycles in the park behind the supermarket and library? ： スーパーと図書館の裏にある公園に自転車はありますか？
== Are there bicycles in the park? ： 　あの公園に自転車はありますか？
　　┗ + The park is behind the supermarket. ：　+ その公園はスーパーの裏にあります。
　　┗ + And the park is also behind the supermarket. ：　+ また、その公園は図書館の裏にある、とも言えます。
　→　スーパーの裏にある、そしてまた、図書館の裏にある、という公園に、自転車はありますか？
　　　　↓
　→　スーパーの裏、や、図書館の裏、…にある公園に、自転車はありますか？
　　　　↓
　→　｛スーパー　や　図書館｝{の裏}、…にある公園に、自転車はありますか？
　　　　↓
> 「スーパーや図書館の裏にある公園に、自転車はありますか？」

…………

I feel that "自転車は公園の中のスーパーと図書館のうしろにありますか" is ambiguous.
> 自転車は、{[公園の中のスーパー] と [図書館]}の うしろ　に　ありますか
　┗ behind [the supermarket in the park], and behind [the library] as well
> 自転車は、{[公園の中]の　[[スーパーと図書館]]}の うしろ　に　ありますか
　┗ behind { [the supermarket] and [the library] }, in the park

And it wouldn't show "Are there bicycles in the park," I think.

not > 自転車は、公園の中 …{のスーパーと図書館のうしろ}… にありますか
　　　（自転車は、公園の中にありますか？）

Thank you for the corrections, I am sorry it took me so long to respond as I had fallen ill. Upon reflection my teacher was not speaking very fast, but I was struggling even with their normal speed japanese. I need to practice listening at normal speeds. I was just frustrated and lashed out a little. Please approach your style with your students as you feel is appropriate.