There are many products on the market now that can deal with this situation.
But first I'd like to ask if it's a general whole side of a floor that is high or just the odd high spot? If it's just the odd high spot it's far more economical to shave the high spots lower to reduce the amount of compound required to level the whole floor. If however it's a case that the whole floor simply lays off tilt so to speak and you have no height constraints on the low side then there are lot of options regarding levellers.
Be that the case the best way to tackle this is to insert screws with raw plugs in a grid formation of roughly 1 metre part to a level height using a spirit level from a starting point which will be the highest part of your floor slab as a 'level' reference. Then follow the instructions of the levelling product with consideration to surface prepperation,i.e. Priming and contamination etc. Then use a product like BAL level max (up to 80mm in a single application).
A level and flat floor can be achieved in one application if you plan and consider all aspects properly beforehand.
Hope this helps