Production: 1 = (yes), 0 = (no)
Office: 1 = (yes), 0 = (no)
Storage: 1 = (yes), 0 = (no)

CASE WHEN "Production" = 1 THEN 'P' ELSE '' END

P/S

O/S

P/O

P/O/S

regexp_replace(  if("production"=1,'P/','') || if("office"=1,'O/','') || if("storage"=1,'S/',''),'/$','')