On the reference qualifier fields, recent selections are shown. If you wish not to show some of those recent selections on the list, please follow the below procedure.
There is no out-of-box solution to clear the Recent Selections in the Auto-Complete queries. However, there is a manual procedure;
- View records of the sys_ui_recent_selection table, this table stores all "Recent Selections" for specific fields. (https://<instance-name>.service-now.com/sys_ui_recent_selection_list.do?sysparm_query=)
- Select the required field (note that this will apply globally to all users)
- Delete the record (backup if you want to recover)