Second, you need to have the correct entry in your fstab if you are using an NFS mounted share as your datapump directory:
pso:/PSO /PSO nfs rw,bg,hard,nointr,rsize=32768,wsize=32768,tcp,vers=3,timeo=600,actimeo=0 0 0
Make sure the directory itself (PSO in this case) has the proper credentials - it should be owned by Oracle (make sure the group is correct as well) with rwx for all.
Then, create the Oracle server directory that references this directory (or a child of this directory). Note the grant to the schema user 'ARAMARKPURISMA'. This is important if you want to import as the schema user (rather than system).
Then, run impdp and remap tablespaces as needed:
DROP DIRECTORY ARAMARK;
CREATE OR REPLACE DIRECTORY
ARAMARK AS
'/PSO/Customers/Aramark';
GRANT READ, WRITE ON DIRECTORY SYS.ARAMARK TO ARAMARKPURISMA;
GRANT READ, WRITE ON DIRECTORY SYS.ARAMARK TO SYSTEM WITH GRANT OPTION;
Then, run impdp and remap tablespaces as needed:
impdp system/manager@se04 DIRECTORY='ARAMARK' REMAP_TABLESPACE=PDH_LARGE:MEDIUM remap_tablespace=pdh_medium:medium remap_tablespace=pdh_small:medium remap_tablespace=pdh_batch:medium schemas=purisma remap_schema=purisma:aramarkpurisma DUMPFILE=purisma_allobjs_0512.dmp