Blizzard please read the article linked above
and implement wider level ranges as soon as possible. My lowbies can’t even re-queue with people I just did a dungeon with often because one person levels out of the tiny insane range of the dungeon finder in its current implementation.
I believe the number ranges are actually already listed correctly in the game, but they don’t actually work correctly in practice. For example, at level 22, my priest can only get Blackfathom Deeps and Stocks.
According to the number ranges, at level 22 I should actually have access to all of the following dungeons:
Deadmines 15-25
Wailing Caverns 15-25
Shadowfang Keep 16-26
Blackfathom Deeps 19-29
Stormwind Stockades 20-30
Razorfen Kraul 22-32
You should also be able to group queue as long as everyone in the group has at least one dungeon overlapping in their level range.