How to add fields in manage item Ui search and make them mandatory

We want to create a advanced search for searching items which should only consists of 3 fields (Cross Reference, UOM, Country(EFF)). These fields can be currently accessed from add fields column in advanced search. But , since they arent mandatory fields, we cannot do a search using exclusively these fields since there are some fields which are mandatory (Item, description, keyword). We do not want to use these default fields but want to make the required fields mandatory.

How do we achieve this?

Version (include the version you are using, if applicable):

24B