Read this unified guide valid for Bioshock 1 and 2 Remastered:
https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=1659202156
(Small donations 💰 to buy and fix some more games are welcome from my profile page)

If you can't change brighness slider in the game, even if you set the compatibility option "Disable full screen optimization", that's because of Nvidia Optimus.
To be able to change brightness on modern PCs with Optimus mode: iGPU + NVidia dGPU you have 2 choices:
A) use dxvk (Vulkan wrapper) from github
B) switch to dGPU only mode before you run the game (if you have Advanced Optimus you don't need to reboot)