The bug

A /playsound command playing a sound at particular coordinates will be heard by any player near those coordinates in any dimension.

How to reproduce

1. Be in the overworld
2. /tp @s 0 64 0
3. /execute in nether run playsound random.explode @a 0 64 0

Expected behavior
You should hear nothing since the sound was in a completely different dimension from you

Actual behavior
You hear the explosion

Notes
The scripting API makes this bug obvious, since playSound is a function of world instead of dimension