Variables in custom field list filters

Hello, 

I have created relational list custom fields for service records and action items which target users as the entity. Is there a way to set filters on the field using variables to filter the list dynamically? 

For example, I would like to filter the custom user field based on company of the requestor.

This is similar to how the requestor field is filtered by the defined company in the service request, or how the available admins are filtered by the admin group.