You can search on chessgames by player, year and what colour they play, im not sure if you can translate these games into a game explorer but here is an example of Naiditsch's games from 2014 with black:
http://www.chessgames.com/perl/chess.pl?yearcomp=ge&year=2014&playercomp=black&pid=48885&player=&pid2=&player2=&movescomp=exactly&moves=&opening=&eco=&result=
A brief look tells you that he's playing the KID, NID/QGD/bogo/QID combos, and mostly 1..e5 and sicilian najdorf as black.
One problem with such an approach is that the top guys mostly have a huge range of positions they play, and it's tough to disentangle what they regularly play from what might be played for surprise or prepared against a specific opponent.
I'm aware that you can go onto chessgames.com and look up titled players and see what they are playing with for Black and White. However, is there a way to:
(1) filter this so that you see only what they are playing for the past year or six months, for example; and
(2) look at their repertoires of choice -- sometimes it will show that they played, for example, the Sicilian as White when in fact it was Black who chose the line/opening.