Yes. When you create a new message, you can select a list(s) or use the quick search to find specific subscribers.
You can send a message to multiple lists and/or multiple subscribers. The example below shows a message that will send to everyone in the Over 55 list and Jadon and Brooke. ⬇️
You can also message a few subscribers or part of a list by going to the Subscribers page > Choose a list (or click View All next to Subscribers) > Select the subscribers you want to text > Actions > Send message.