CubeMX will not add “st BSP ” for nucleo or disco eval board even if you select thems
you may add the st bsp drivers file in the genererated project by copying the bsp source from the CubeXX package into project folder.
for instance on windows and a discovery f4 the bsp file are here
if you copy all from here in the cubmax src project folder then add the “src” folder as part o fthe include path it may do.
but beware do not enable in cubemx any perif handled in the bsp side it iwll generated conflict
Also you may run into msp init , irq and callback conflict when to enable or use some perif used in the bsp (i2c , spi etc...) because msp code in bsp will conflict with CubMX as it can be only one msp_init/deinit and callback per perif family .
I suspect that is why “bsp” are not hanlde by CubeMX
basicaly st “bsp” are not very friendly to upgraed or re-use as is,
but you can easily look at the st bsp files to learn and copy paste the bit of code you need into your own project (inisde cubemx “user” banner).
To learn you can use the CubeXX bsp example or demo projet as starting point lcoated here
but beware copying and duplicating this projects oustide the “CubeXX” repo may not be easy, also all drivers files are shared among all projects and cubemx so any changes you do here will affect all!