How to add autocomplete filter for multi value entity(USER) reference field?

I have enabled VIEWS AUTOCOMPLETE FILTER module.

I have a field : field_assigned_user which is user reference field and field settings is set to unlimited values.

I have created a relationship entity reference : referenced entity field_assigned_to_user.

I have added a field field_assigned_user which has no relationship and another field: user name having relationship as entity reference : referenced entity field_assigned_to_user.

What should I add in the filter criteria to get autocomplete field for field_assigned_user ?

For entity reference field which is not multi-valued and not an user reference field , the autocomplete field works?

I have referred the video link in the module Drupal 7 Views Autocomplete Filter Tutorial and worked step by step. But for the user reference field no support or help is provided
Just to add to issue , the following occurs when I have contextual filter for that user reference field.