Here's how:
Go to Messages - Bulk SMS.
Click Create bulk SMS.
In the Filter section, select the filters you want to use.
In the Message section, enter your message.
Click Send.
Here is an example of how to use filters:
This business is having a 20% off sale for all services at Location 1 with Harry Potter on Friday.
Note: A single SMS message technically supports up to 160 characters, or up to 70 if the message contains one or more Unicode characters (such as emoji or Chinese characters).