Like in which adventure paths can I find them in?
Emerald Spire is the largest one that is completely detailed afaik, from Paizo for PF 1e.
I could be wrong, but I think:
Emerald Spire (entire book is one connected dungeon)
Shattered Star (entire AP is mostly one huge dungeon?)
Scarwall Castle (book 5 of Curse of the Crimson Throne) is a massive castle
Briarstone Asylum (book 1 of Strange Aeons) is a large building
The final book of Mummy's Mask is a series of dungeons in one place, if that counts?
The final book of Kingmaker, but that's a demiplane rather than a dungeon
Shattered star: 90% of each book is a seperate dungeon, so 6 in total.
Book 5 of Rise of the Runelords is 80% one massive dungeon.
If you want to branch away from Paizo products, there's a book out there entitled "World's Largest Dungeon", a huge tome that is one giant dungeon, and IIRC rules neutral.