You go on the map. From the display options section you check Show Attack Planner.
Now you will have a list with all the players of your tribe. You go to the one you are interested in, change the color (I used more colors / more players for this demonstration).
If you want to mark Attack or Fake villages for that player you use the two options you have over the column of names. The next step, you go to map and select one by one (or drag) the villages that player must attack. You click once, the village will be marked with an A in the player that is selected color. You click twice, the village is marked with an F (for Fakes) in that player's color.
If you go to Rally Point and select Attack Planner you will see what villages were assigned to you. Although you won't see which as fakes or which as attacks. You can see that though if you go to map. A player can see all his tribe's attack planner. So if you work on a plan for an OP anyone in your tribe can see it just by going on the map.