Currently, when searching for members in the Member GUI for the organization, the characters entered in the "Search" box will only return correct results for those members that have the searched string at the beginning of their First Name, Last Name, or username. This limitation is not documented anywhere and not only reduces the power of the search tool, it can lead to incorrect expectations and confusion regarding its results.
For example, the username Johnsmith_agol would only come up if searching using "J" "Jo" "Joh" etc... Searches like "_agol" or even "ohnsmith_agol" will not return the result. This issue is documented in Tech Supprt Case https://my.esri.com/#/support/cases/tech-cases?caseNumber=03988615. Development has reviewed an enhancement request (https://my.esri.com/#/support/bugs/bugs?bugNumber=ENH-000107730) for usernames containing the searched characters anywhere to return as results, and have closed that request out and will not be addressing it.
This Idea is to solicit support for a search tool that finds the searched characters if they occur anywhere in the target fields. Use cases are many, but one example involves trying to find all members that were incorrectly assigned usernames with an organization shortname in all lowercase appended to their SAMLID, contrary to our New User Defaults (this was due to a BUG https://my.esri.com/#/support/bugs/bugs?bugNumber=BUG-000179029). Because the characters occur at the end of the username, they are unsearchable. Another means of finding the affected members must be employed.
A search tool should find what it is looking for. Or at the very least the cases where it won't should be documented.
Note: this is related to this quite old Idea- https://community.esri.com/t5/arcgis-online-ideas/agol-admin-make-user-filters-work/idi-p/937925
