Enterprise User Security (EUS) allows Oracle Database to use users & roles stored in LDAP for authentication and authorization.
Since the 11gR2 release, OUD natively supports EUS. EUS can be easily configured during OUD setup. ODSM (the graphical admin console) can also be used to enable EUS for a new suffix.

However, enabling EUS for a new suffix using command line interface is currently not documented, so here is the procedure:

Let's assume that EUS support was enabled during initial setup.
Let's o=example be the new suffix I want to use to store Enterprise users. The following sequence of command must be applied for each new suffix:

// Create a local database holding EUS context info
dsconfig create-workflow-element --set base-dn:cn=OracleContext,o=example --set enabled:true --type db-local-backend --element-name exampleContext -n
// Add a workflow element in the call path to generate on the fly attributes required by EUS
dsconfig create-workflow-element --set enabled:true --type eus-context --element-name eusContext --set next-workflow-element:exampleContext -n
// Add the context to a workflow for routing
dsconfig create-workflow --set base-dn:cn=OracleContext,o=example --set enabled:true --set workflow-element:eusContext --workflow-name exampleContext_workflow -n
//Add the new workflow to the appropriate network group
dsconfig set-network-group-prop --group-name network-group --add workflow:exampleContext_workflow -n

// Create the local database for o=example
dsconfig create-workflow-element --set base-dn:o=example --set enabled:true --type db-local-backend --element-name example -n
// Create a workflow element in the call path to the user data to generate on the fly attributes expected by EUS
dsconfig create-workflow-element --set enabled:true --set eus-realm:o=example --set next-workflow-element:example --type eus --element-name eusWfe
// Add the db to a workflow for routing
dsconfig create-workflow --set base-dn:o=example --set enabled:true --set workflow-element:eusWfe --workflow-name example_workflow -n
//Add the new workflow to the appropriate network group
dsconfig set-network-group-prop --group-name network-group --add workflow:example_workflow -n 

// Add the appropriate acis for EUS
dsconfig set-access-control-handler-prop \
          --add global-aci:'(target="ldap:///o=example")(targetattr="authpassword")(version 3.0; acl "EUS reads authpassword"; allow (read,search,compare) userdn="ldap:///??sub?(&(objectclass=orclservice)(objectclass=orcldbserver))";)'
dsconfig set-access-control-handler-prop \
      --add global-aci:'(target="ldap:///o=example")(targetattr="orclaccountstatusevent")(version 3.0; acl "EUS writes orclaccountstatusenabled"; allow (write) userdn="ldap:///??sub?(&(objectclass=orclservice)(objectclass=orcldbserver))";)'

Last but not least you must adapt the content of the ${OUD}/config/EUS/eusData.ldif  file with your suffix value then inport it into OUD.