Unfortunately it looks like BSSP compsets were removed sometime in the CESM2.2 development, and we haven't added it back in. These compsets are available for CESM2.1 release series, and will work there. Most of the components in CESM2.2 and following probably do recognize SSP scenarios, but you would need to do some work to get full BSSP compsets working. You could use the CESM2.1 release version to help see what you would need to do in CESM2.2...