This is a port of the Metazelda dungeon generator by Tom Coxon.
You can create dungeon template shapes using the Unity tilemap editor.
A couple screenshots:
https://github.com/jmuzz/metazelda-unity/blob/master/Assets/Screenshots/ss1.png
https://github.com/jmuzz/metazelda-unity/blob/master/Assets/Screenshots/ss2.png
https://github.com/tcoxon/metazelda
Detailed and easy to read explanation about how this works: http://bytten-studio.com/devlog//2012/11/30/lock-and-key-puzzle-generation/
How Tom built the overworld generator on top of this for his game Lenna's Inception, and a comparison of that to some popular roguelikes: http://bytten-studio.com/devlog/2014/09/08/overworld-overview-part-1/
Tom's Blog, mostly about Lenna's Inception: http://bytten-studio.com
These 3 tutorial video series will teach you everything you need to know about how the project is set up.
https://unity3d.com/learn/tutorials/topics/2d-game-creation/introduction-unity-2d-perspective
https://unity3d.com/learn/tutorials/s/2d-roguelike-tutorial
https://unity3d.com/learn/tutorials/topics/2d-game-creation/intro-2d-world-building-w-tilemap