Make sure you have The City DLC purchased, or that it's on rotation for free trial, and activated for the game. Choose the Tavern Maid as your character. Add four local players that you can control, and set all of them also as the Spy character.
Set the Spy characters to start in the City, then once they get to move, try to position two pairs of Spies within five places of the Tavern Maid. (The Spy's "Shadow" ability makes them able to move directly to another character, which guarantees you two pairs of Spies.) Having two pairs instead of one makes it more likely to get a pair closer to the Tavern Maid.
When the Spies are positioned, roll to move for the Tavern Maid. Make sure she gets a number higher than(not equal to) where one set of spies are positioned. Reroll if you have to. If you still don't get a high enough number, quit the game and then resume it from the menu, and you can roll and reroll over again.
Once you roll high enough to get past one pair of Spies, don't move to that space. Instead, click and travel to the pair of Spies you would've otherwise passed. The Tavern Maid will move there, and you'll see an option to pour them a drink. Do so, and you'll unlock the achievement.
This should only take a couple of minutes to unlock.