Snead was pretty candid this past year how they worked the board.
Probably like most teams, they put guys in pools who are close enough together that depending on team need, they choose the best combo of value and team need. But, if a player is sitting there that does NOT meet a need, but he's an entire tier higher than a pool of players where someone DOES fit a need, they'll take the guy in the higher tier especially in the earlier rounds.
So I suspect that about the only positions they would NOT take in round 1, for instance, would be QB and RB. And probably they would not take an OL other than an LT prospect. Round 3 might also be slightly more position targeted, but only to a point. After that you're typically looking at depth players.