O_O
Hm.... well I never had to hide my diapers from my parents, and only told a few of my friends whose houses I wanted to sleep over at.
When I had them at home, I found my emptiest drawer and placed the diapers in a layer on the bottom of that drawer. It kept them easily accessible and out of sight.
When I had to take them on sleepovers, I put them in my gym duffel bag, often wrapped in a night shirt. I was never "caught," per se, but my friends who I stayed with, I told early on. They made gentle fun of me but i was the "girl" in a group of boys. They understood the bedwetting was a rather sensitive topic for me and kinda treated me like the kid of the group in general, in good ways.
But it's not always that easy, I know.