I've got one of those interesting escape buttons which unscrews to reveal a little compass. Mine happens to be an army "General Service" pattern button, and I have certainly seen RAF and RCAF buttons with the same arrangement.
What has always intrigued me though is what use they really were? Other than early on in the war, say up to the end of 1940, RAF aircrew didn't fly in No 1 uniforms, which were the only ones to have brass buttons, and similarly army troops, including officers, would be wearing battledress when in the combat area, not service dress. Was this one of those ideas which looked great on paper, but in fact was never of any practical use? Did anyone, in fact, ever use to one to assist an escape? Or were they a bit like all those saucepans which got melted down and were never turned into Spitfires!