Filtering for contacts or contactgroups lists hosts they're not notified about

Describe the bug

Filter in the host list for contacts or contactgroups. You'll notice that you get hosts where such a contact or group is notified about one of its services. They are not notified about the host, however.

To Reproduce

1. Have a host
2. Have a service on that host
3. Configuration notifications for that service
4. But not for the host
5. Search with user.name=... in the host list

Expected behavior

• The host doesn't appear in the host list (host.user.name)
• The service appears in the service list (service.user.name)

If such a filter is used as restriction:

• Clicking on the host link (service list) or host tab (detail) a 404 appears

Additional context

ref/IP/52109