Mad Hatter, Jervis Tetch
Pay 1 resource point -> Move target character with cost 2 or less to your front row. At the start of the recovery phase this turn, that character's owner moves it to his front row. Use only once per turn.

If I target my opponents concealed 1 or 2 drop, can I move it to my visible front row? If yes, can they move it back to their concealed area when it goes back or would I choose which area it goes to?

When moving a character, unless the effect tells you differently, they move to the same kind of area that they moved from. Visible to visible, or hidden to hidden.

Mad Hatter is just moving the character, not having it leave/enter play, so it can't change the type of area. Which also means it doesn't matter if the character has concealed or not, it only matters if the character is hidden or not.