The "Domain Access" setting allows you to control whether to restrict participation to employees on your employee file only or extend it to everyone with SSO access. 

Here's what you need to know:

• Dialogue uses your employee file to build the custom pulse audience.
• By default, “Domain Access” is turned off and participation is limited to employees on your employee file. 
• In certain cases, you may want to allow employees with SSO access, even if they are not on your employee file, to participate. Enable “Domain Access” to accommodate these employees and broaden the participation scope.