Yes, you can! It is allowed to share the route plan with the people you are traveling with, as long as they are part of the same travel group.
If you are traveling with one car, you can share the route plan with everyone in that car. However, if you are traveling with two cars, you need to purchase two separate route plans.
Sharing the route plan with others outside your travel group is not allowed.
You can easily open the route plan on different devices, such as phones or tablets, so everyone in your group can use it for navigation during the trip.