Using advanced search enables to you filter your contact data and identify a specific group for a targeted message. As long as you have the data, you can use it to filter your contacts.
An example of an advanced search - searching for any contact with a GPA above 3.0
After you have your criteria set, your contact list will filter only to include those that match the results. Additionally, if you are going to be reaching out to this filtered list over time, you can save this search criteria by clicking on the arrow next to the search bar, choose the option to save this search, and type in a name when prompted.
To access your saved searches, just click on the arrow and choose your filter name from the list. The contact data will refresh and you'll be able to send a message to your current results.