when copying items, triggers or graphs, there is a "Target type" dropdown. it has entries "Hosts" and "Host groups".
to users this essentially looks as if there is no way to copy to templates - but actually templates are hidden under hosts... (i'm not even sure whether copying to "host groups" would also copy to templates, happening to be in those groups )

there should be entries hosts/templates/groups and they should only copy to corresponding entities. in the future we might want to split host groups/template groups, but that is out of scope for this issue.

this is a bug, not a feature request, as templates are hidden under hosts. users get confused about this very often.