Put the summary of the bug you're having here
What I expected to happen was...:
/execute command would target players in a specific when targetting a player in a specific dimension.
What actually happened was...:
it didn't.
Steps to Reproduce:
1. /execute if entity @r in minecraft:[dimension] run [command]
2. press enter
3. be disappointed when it targets all dimensions
"if entity @r" is separate to "in minecraft:[dimension]". What is happening here is that you are detecting whether a random player exists and, if so, then running [command] in [dimension].
Fix for this:
84853000 is only really necessary if you're running this from the corner of the world and trying to look for a player at the opposite corner. In reality a much smaller number (say 10000) is needed, depending on your world size.