If you find the ST page describing the nucleo board, you will be able to download some zip files. Inside one of them should be the Altium reference project files.
This should also be the same for Discovery and Eval boards.
Thanks you all for the feebback - the schematics, applicaiton note helped a lot. Also whether similar schematics available for the STM32L4R7 series. Since mine design need a compatibility between STM32H743ZI and STM32L4R7ZI