DataAssist Search soes not have the ability for grouping search items.
but, if you don't enter a value in one of the form element, that column wont be included in the filter that is generated.
In other words, if you enter a number of bed rooms, but don't enter anything in the square feet, it wont include square feet in the filter that is created.
just make sure when use select lists, that you include a blank value option:
<option value="">make A selection</option>