In Cisco ISE version 2.3 Policy interface changed dramatically introducing significant learning curve especially for people used to work with the older version.
One of the questions I had after migration from 2.x to 2.3 was how do you edit migrated Library Conditions. Prior to 2.3 you would select condition > edit and make any changes needed. In 2.3 when I got into Policy Elements > Conditions and noticed there is no edit.
To make changes to the existing condition we actually have to drag it over to Editor to be edited.
If you want to add a similar element within the same condition be careful and do not click the wrong button.
Instead, click Edit on the condition itself
Click Duplicate next to Library element to be duplicated.
A new line will be added. Populate it with the new value and click Save. Do not forget about logical OR / AND.
On the next screen, you should never be prompted to create New Condition. If this happened then you clicked wrong Save button.
Close out of this dialog and click Save button all the way at the end of condition. This time condition name should appear without any prompts. Click Save again.
Now condition is finally updated with the new value.