If you have a Hamlet, Watchtower, and Tunnel in hand, you should be able to do this:
Play Hamlet.
Discard Tunnel for +1 action, revealing Tunnel to gain a Gold, revealing Watchtower to put the Gold on top of your deck.
Discard Watchtower for +1 buy.
However, in the current UI the behavior is:
Play Hamlet.
Select "both" to discard two cards.
Select Tunnel and Watchtower.
Reveal Tunnel to gain a Gold. There is no prompt to reveal Watchtower, so you can't topdeck the Gold.
This happens because the Hamlet UI does not really follow the card rules, where each discard is a separate step. Instead it asks:
Discard for Action
Discard for Buy
Both
Don't Discard
(I'd suggest prompting as follows to adhere to the rules and still be reasonably convenient:
First prompt:
Discard for Action
Discard for Buy
Don't Discard
Second prompt, only appears if you selected "Discard for Action":
Discard for Buy
Don't Discard
So if you want to discard twice, you can pick Discard for Action the first time, then Discard for Buy the second time.)
As the discard options on Hamlet are two separate effects, this is indeed a bug in the new client. DXV has confirmed that you can react separately: http://forum.dominionstrategy.com/index.php?topic=1004.msg15441#msg15441 (http://forum.dominionstrategy.com/index.php?topic=1004.msg15441#msg15441).
So for full compliance with the rules the client needs to do/have one of these:
- discard the first selected card first implicitly (still allowing to react with the second selected card), or
- an ordering box after [Both] (discard the left card first, still allowing to react with the right card), or
- separate steps for [Discard for +Action]/[No Discard for +Action] and then [Discard for +Buy]/[No Discard for +Buy].
With any variant, the direct click on a green-bordered action card could still be used for [No more Discard for this Tunnel].
With the current card set, the ordering box is only required if a Tunnel and the only Watchtower in hand are selected. Actually, to make it easier, the Tunnel could be always discarded first automatically, I guess, even if that would technically be stealing a decision from the player.