Field in Object links to another object in the same 'table' - How to do a lookup?

For what it’s worth, I’d suggest changing the text of the “Search fields”, which is “Use Search Fields to specify which fields to search on. If you do not specify any fields, all searchable fields will be searched.” to mention that it also controls what displays on the pop-up.  I looked everywhere I could think of to find how to specify the fields.