Search all groups and projects in the global search filters
From https://gitlab.com/gitlab-org/gitlab-ce/issues/30214:
The Group and Project filters in the search page should be able to search/show all of the instance's groups and projects.
Currently, the filter dropdowns only return groups or projects that the user is a member of. If the user wants to search within a group or project that they are not a member of, that is currently impossible.