I cannot tell you for certain, since it is your system and not mine, but just a guess...
/db2/BWD --> base directory of the system
/db2/BWD/db2dump --> where db2diag.log and other dump files are placed
/db2/BWD/log_dir --> your working log directory
/db2/BWD/log_archive/...../NODE0000/C0000000-- --> your archive log directory
/db2/BWD/sapdata1 --> one of you tablespaces
/db2/BWD/sapdata2 --> second tablespace
/db2/BWD/sapdata3 --> Third tablespace
/db2/BWD/old_archive --> old log archive directory
Andy