You will need some real pro help . We have a sloped yard with an above ground pool we have the yard levelled waited a year with a lot of tamping done on the grous to make sure whe n installed the pool it would not shift . We have deck built all around ours and around the house so the deck is different levels . Our pool has been in for 16 yrs not one issue with shifting so I think your idea could work but I would check about an actual pool . We could not do that in our yard becuae we have gas lines crossing our property . Or check out swim spas This is my pool the trees you see on the right are 20 ft tall

A fiberglass infinity edge plunge pool.

The short answer is that it can totally be done (I live in the Hollywood Hills - almost everyone has an partial in-ground pool on a slope!) - it's just that the cost to put in a pool can be pretty high depending on your site specifications - you have to consider site access, surveys/soil testing, additional structural support (we are required to have a deepened foundation under our pool - like caissons, etc.). We've been exploring options with different types of pools (there is a company called Soake that specializes in cast concrete plunge pools - they deliver them directly to the site - pretty cool if you are on the East Coast) - but for our lot, they don't result in enough savings compared to traditional pool installation. There are also steel pools ($$$) that are available. Again, your site preparation is what will likely drive up the expense of the project.

Some option