Issue Summary

Currently, if you deactivate/remove a user from your site, you won't be able to search for their shared dashboards/filters; although you can extract this data using REST API, this can be time-consuming. 

It would be great to search for deactivated users who own shared dashboards/filters through the UI instead of using REST API.

Steps to Reproduce

1. Create a dashboard/filter and share it with your organization.
2. Deactivate/remove the user used to create it.
3. Try to search for the owner; even if the dashboard is available, you can't search for the owner's name. 
   • The same behavior can be observed under Settings > System > Dashboards/Filters.

In the example below, the user "Joe Doe" was deactivated:

Workaround

You can use REST API endpoints to search for shared dashboards and filters deactivated/removed users' own as a workaround.

Dashboards:

• GET: Search for dashboards

Filters:

• GET: Search for filters