The game doesn't really provide an integrated way to see where you're getting farmed from but there is a way. After you get attacked check your battle report and tap on the revenge button. From there you'll be prompted to select how many troops you want to use. You can use however many you want, but if you just want to see the coordinates just send 1 swordsman. Your march queue will show where you are attacking to. That way you only lose one swordsman.
Taken from a comment I posted completely unchanged because I'm hella lazy.