The best example I can offer, is the very last criterion field in the Library of Congress’ Chronicling AmericaAdvanced Search page, which I use constantly.
There, I can search for instances of [Word-A AND Word-B] in which no more than, say, five words are in-between the two. This feature is a godsend for research in the humanities. Can DT do this now and/or is this a feasible feature to recommend for future builds? Thanks!