I don't think you can eliminate one of the DMax function's required parameters, and as far as I know, you must provide the field AND the domain. Criteria is optional. Use the syntax
DMax ( expression, domain, [criteria] )
You will find most of the similar functions here - suggest you bookmark the page or go to the parent site page and see what else is there that might interest you. It will save you time waiting for replies that you could easily discover the answer to.
Good luck.
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.