You need to monitor the Audit logs by external software (such as QRadar). For each of the below, you need to monitor by a database query if available.
Checking the following Doc, you don't find what you need:
Monitor user login attempts in DX UIM Operator Console (OC)
You could monitor the log files mentioned in the following sections using logmon probe. For information on using logmon probe, refer the Additional Information section.
Apr 02 01:53:53:309 DEBUG [http-nio-8080-exec-6, com.nimsoft.nimbus.probe.service.wasp.auth.LoginManager] non-contact user found: administrator
Apr 02 01:53:53:309 INFO [http-nio-8080-exec-6, com.nimsoft.nimbus.probe.service.wasp.auth.LoginManager] authorizeNimbusUser: user: administrator
Apr 02 01:53:53:671 INFO [http-nio-8080-exec-6, com.nimsoft.nimbus.probe.service.wasp.auth.LoginManager] nimbus user authentication successful
Apr 02 02:00:05:705 DEBUG [http-nio-8080-exec-6, com.firehunter.ump.auth.OCAuth] Login from request usr uimoperator
Apr 02 02:00:05:707 DEBUG [http-nio-8080-exec-6, com.nimsoft.nimbus.probe.service.wasp.auth.LoginModule] User 'full domain access/uimoperator' trying to log in.
SELECT account_id FROM CM_ACTIVE_ACCOUNT WHERE login_name = 'uimoperator'
Apr 02 02:00:05:944 DEBUG [http-nio-8080-exec-6, com.nimsoft.nimbus.probe.service.wasp.auth.LoginModule] uimoperator logged in.
Apr 02 02:00:05:944 DEBUG [http-nio-8080-exec-6, com.firehunter.ump.auth.OCAuth] User: full domain access/uimoperator, NimBUS login milliseconds: 237
May 26 14:33:28:236 [14192] 0 hub: (nim_ldap_query) ldap_search_ext_s(base:=CN=<user name> (exampleuser),OU=Externalsite,OU=xxxx,DC=xx,DC=xxxx,DC=xx scope:=LDAP_SCOPE_BASE filter:=(objectclass=*) attrs:=userPrincipalName, memberOf, name
May 26 14:33:28:236 [14192] 3 hub: (nim_ldap_query) ldap_search_ext_s: LDAP_SUCCESS
Apr 12 13:46:43:214 INFO [http-nio-8080-exec-2, com.nimsoft.nimbus.probe.service.wasp.auth.LoginManager] authorizeNimbusUser: user: administrator
Apr 12 13:46:43:592 INFO [http-nio-8080-exec-2, com.nimsoft.nimbus.probe.service.wasp.auth.LoginManager] nimbus user authentication successful
More information on logmon probe: