Asset Metadata - auto complete text field

Hi,

Requirement is to have a auto-complete text field in Asset metadata editor to enter user name.

Author should be able to enter user id/name, which gets validated against external user list in LDAP and show suggestion list with  available users.

Ex - Author enter text string as "adm", he will get list of the usernames start with "adm".

(External users - users who are not in AEM user list).

AEM provides Authrizable field, but it is limited to AEM internal users.

/libs/granite/ui/components/coral/foundation/authorizable

AEM 6.4 (SP-4)

Example -

Any suggestions/examples please.

Thanks.