First and foremost, you'll need to start by creating your Broadcast.
You can find out how to get started by reading the overview on Broadcasts.
With our latest update to Broadcasts, you can now send an individual Broadcast to multiple Groups and Contacts at the same time.
Selecting Multiple Groups and Contacts
Once you have named you're Broadcast, you'll want to choose who it is going to get sent to. Click on the empty box below the 'To:' section, this will allow you to search for the Contact(s) and/or Group(s) you'd like to receive your message.
Now you'll need to search for the Contact(s) and/or Group(s), once you've searched, you can click on the contact or group that you want to send to. Once you've selected all of the Contacts and/or Groups, you can click 'Done.
Create a Group or Contact while Creating your Broadcast
While you are creating your Broadcast, you may not have the Group or Contact created already that you want to receive the message.
In that case, you can search for the Contact or Group that you'd like to add, if you can't find them the option will appear to Create the Contact or Group you need.