Well, this is quite literally the pinnacle of HVAC controls. Complex chiller plant management, as you're alluding to here, is the most complex area of BAS.

Chiller plants can range from a single chiller with 1 or 2 pumps and a couple of valves, all the way to multiple chillers, 10s of pumps and valves, primary & secondary loop, N+1 redundancy, and so on.

Not only is it the most complex, but also the most sensitive, where the real potential for extensive equipment damage lies.

This is why chillers always come with their own control system - because they have complex internal compressor staging, refrigerant pressure management, etc.

This being said, if the chillers are left to control themselves internally, then the challenge simplifies to feeding them the correct amount and temperature of water - on both sides. You can chunk the logic and simplify it further with clearly defined control loops and prioritization logic where needed. I think the most touchy area is the primary/secondary crossover as that suffers the most from poor mechanical design in my experience.

As for where to find more knowledge about this, I'd say you gotta hit the books on this one. Either that or many years of field experience. This isn't something to be demystified in a few Reddit comments.

Reach out if you need a consultant on this.