I don't think 'hash_for_system_path' will work since the page that you are redirecting to is a bastion (angularjs) page.  Instead, you could use something like the following:

```
<% subscriptions_path = '/content_hosts/' + Katello::System.find_by_host_id(@host.id).uuid.to_s + '/subscriptions' %>
<a href=<%= subscriptions_path %> class="btn btn-default" title="<%= _('Content host subscription details') %>">
  <%= _('Subscriptions') %>
</a>
```

I have tried this locally and it worked Ok for me.  That said, it needs to be extended for the authorization, which you may be more familiar with.