Can I build a masking shader to compile multiple materials in a pattern?

Good morning!

I've never written a shader before and am absolutely unfamiliar with what Unity's material system is capable of and, so far, none of my research has yielded any helpful information.

My problem is that I need to apply up to 4 different substance materials to a single surface in multiple different patterns like a herringbone, checker, maze, etc. I'm trying to figure out if its possible to do so with a shader that can mask and layer these materials together on a single surface. It would also have to be updated at run-time by user selecting materials.

My question is: Is this scenario possible with Unity's material system? And, if so, where can I start developing one?

Many thanks to those who read and respond, this is a pretty big issue at my job and I'm woefully unprepared to solve it. Otherwise I hope you all have a fantastic weekend!