External identities can be added to a users profile a couple of different ways. For example, if you have LDAP properties that need added, you can manually run a sync to update the new attributes for users, as discussed more here: Core Help, or if there is a nightly sync, that will update it as well.
For SAML external identities, this should be picked up at the time of the user log's in.
If you want to change the value, you can proceed with the following steps as referenced here: https://community.jivesoftware.com/docs/DOC-130040#jive_content_id_External_Identity_changes
- Delete the external entity record from the user's profile within Jive's Admin Console
- Go to Admin Console: People > Settings > Single Sign-On > SAML > General and update Username Identity setting to Enabled
- Please note, when you do this verify that you are not changing the value used for mapping the Username in Jive. This must stay the same for this process to work.
- This is needed to ensure Jive is able to associate the SAML SSO user to the Jive user while the external identity is being changed
- Change the field in your SAML SSO IDP
- Have the user log back into Jive
Hope this helps.