Changing the search parameters in search preview/seach and select for Contact?

We are a high case/enquiry service based organisation that is using the Sugar Serve case module.

When our team are adding Contacts to their case, the default search within that field is currently only search by first name and reveals up to five results. Can this search default parameter of 'first name' be changed i.e. we have a lot of contact named 'Jane', but if we could search First name & Last Name, then identify 'Jane O'Brien' instead of 'Jane Smith' would be quicker.

Currently, we always have to click 'Search and Select' and then filter the search in order to identify the correct contact.

I've just read in the Product Guide that there should be a default filter on the contact list search so it's set to the Organisation that is linked to the Case but this isn't enabled in our version - need to look into this too.

Any help on this would be great - done a lot of searching in the product guide but nothing that speaks to config of parameters of the Search and Select function.

Cheers,

Sage