Hi,
VisualGDB stores this information in the .vgdbcmake files. This is more powerful than the regular CMake presets, as VisualGDB supports orthogonal configurations/platforms, each of them able to override project-level, build-level or debug-level settings. E.g. you can define multiple platforms for Embedded vs. Linux vs. Win32, and multiple configurations for build types.
You can find more about platforms in CMake-based projects in the Linux platform tutorial and the simulation platform tutorial.