We've just started testing one of the features you've wanted the most: boards within boards. Soon you'll be able to add sections to your boards, making it easy to organize Pins the way you want to.
If you don't have access to sections just yet, hang tight. We plan on making them available to everyone once we're done testing them out.
If we asked you to test board sections, grab an iOS device (or go to Pinterest.com) and tap into one of your boards. Then tap Add section to pick Pins to add to a new section. After you give your section a name, you're all done! Be sure to give us some feedback after trying it out.
Having trouble seeing sections on iOS? Make sure you're on the most updated version of the Pinterest iOS app. If you're still having issues, try quitting the app and reopening it.
Want to try out board sections? Let us know!