You have two questions; the first is how to accomplish your game, but that's not really something anyone can answer in a forum post haha. I'll try to provide some info on your second question "How can I require both the trigger and button press hold of a specific player?"
Differentiating players shouldn't be too difficult with Playmaker; not sure about Corgi though. Using "Collision2D Event" or "Trigger2D Event" actions, store the collider to get the player object that triggered the collision as a game object variable, then get the tag of that player with "Get Tag" to differentiate between Players 1 and 2. You can then use a "String Compare" action to send an event based on which tag you got. Then it's just a matter of telling the player what you want them to do.
That is a very simple way of differentiating players, but there are loads of ways you could go about it. As I said earlier, it's not really possible to explain how to accomplish your entire game here, but if you have more specific questions, I'm sure there are plenty of people around that would be happy to help.
Have a good one, and good luck with your project.