I sometimes see this particle and I know that in those cases it's not used for "or" and yet I can't find what it means. Please help

Example:
俺達がどこにかくれてるかわかるかい？

I think it translates to something roughly like "Do you know where we are hidden?"

It's called an 'embedded question' so if you look for that term in your grammar book or sites, you'll find plenty of information on that.

And your translation is just fine.

There's an embedded question in the English too.

俺たちがどこにかくれているかー＞Where are we hidden
わかるかい？　ー＞Do you know?

The sentence overall doesn't have to be a question of course.
It can be an instruction or a statement 'Find out where they are hidden.' 'I know where they are hidden', etc.

Ah, finally!!! For a long time now I was scratching my head not getting what it really meant. Thanks