[KevinH]

At this time this is not something you can config. You would need to edit the code (ZmContactView.js):

ZmContactView._selectFields = { 
	"fileAs": [ 
		{ name: ZmContact._AB_FILE_AS[ZmContact.FA_LAST_C_FIRST],				selected: true  }, 
		{ name: ZmContact._AB_FILE_AS[ZmContact.FA_FIRST_LAST], 				selected: false },
		{ name: ZmContact._AB_FILE_AS[ZmContact.FA_COMPANY],					selected: false },
		{ name: ZmContact._AB_FILE_AS[ZmContact.FA_LAST_C_FIRST_COMPANY],		selected: false },
		{ name: ZmContact._AB_FILE_AS[ZmContact.FA_FIRST_LAST_COMPANY], 		selected: false },
		{ name: ZmContact._AB_FILE_AS[ZmContact.FA_COMPANY_LAST_C_FIRST],		selected: false },
		{ name: ZmContact._AB_FILE_AS[ZmContact.FA_COMPANY_FIRST_LAST], 		selected: false }
	]
};

Of course in a production install you'd need to edit ZimbraMail_all.js and then rezip it.

zip -c ZimbraMail_all.js > ZimbraMail_all.js.zgz