When you’re dreaming of maps, it means you expect to travel. Perhaps in waking life, you received stimuli about traveling. You may have thought about it, or discussed about desires to see a destination. Sometimes in your dream, you might be able to see a destination, which is your desired place to travel to. In waking life, you might have a goal to visit a certain destination, for a purpose. This information is stored in your memory, which is then activated to be replayed in a dream.
Some dreamers think that when they see the image of a map, it is a clue to hidden treasure. This is less likely to be true, unless that person has received stimulus (heard or seen information) related to finding treasure.
Some dreamers relate the image of a map to their destiny/ fate, and where they have to go. This interpretation is possible. In waking life, the person may have information that they then process in their brain. At night, they dream with the processed information, to relay the intuition.