You can create Chromebook policies to assign endpoint profiles to domains of Chromebook endpoints. The Chromebook Policy > Manage Chromebook Policies page provides a comprehensive summary of which policies are applied to which groups within the Google domain.
This option is only available if you enable the EMS for Chromebooks Settings option in System Settings > Server.
Chromebook policies function identically to Windows, macOS, and Linux endpoint policies except that you apply them to Chromebook endpoints and can only include a Chromebook profile, not a Telemetry gateway list. For details on configuring a Chromebook policy, refer to the equivalent sections in Endpoint Policy.