I've created an Asset Layout called "Firewall"
I've created an Asset Layout called "License" which has a field with an Asset Link that allows me to associate it with any Asset Layout. This could be people, hosts, or Firewalls.
When I search for an Asset using the term "Firewall" it does not return my assets in the Firewall Asset Layout unless their name contains "Firewall"
Also, the same goes for a general search, but it is slightly less of an issue because I can always navigate to the Firewall asset layout directly.