Tablespace 'XXX_SML_INDEX' does not exist using impdb
Find the default tablespace at database level (which is not necessarily the default tablespace of your user):

SQL&gt;  select property_value from database_properties 
      where property_name = 'DEFAULT_PERMANENT_TABLESPACE';

PROPERTY_VALUE
--------------
USERS


Find the default tablespace for your user while logged in another user with adequate privileges for querying DBA_USERS:

SQL&gt; select default_tablespace from dba_users 
     where username = 'BP';

DEFAULT_TABLESPACE
------------------------------
USERS


Find the default tablespace for your user while logged in as that user:

SQL&gt; select default_tablespace from user_users;

DEFAULT_TABLESPACE
------------------------------
USERS


Using that information, remap the tablespace as: remap_tablespace=XXX_SML_INDEX:USERS.