A new feature for those with Group subscriptions (23rd Feb 2018)...
Group members can list Public and Shareable resources uploaded by other Group members, provided those resources have been shared with the group.
This means that Group subscribers can finally share the work of resource creation and adapt materials already created by group members, without having to make their resources public!
You can access group resources by going to Search > My resources and then changing the selector from "just me" to "group". You can also search by group member, by tags, by search terms etc.
To share a resource with other group members, simply select the "Share with group" option (see below) when you upload a resource.
You can edit your existing resources by going to Search > My resources and clicking the "Edit tags + resource type" button for each resource. On the pop-up screen, simply select the "Share with group" option (see below) and then save the changes.
You can also create challenges based on shared group resources, by changing the selector at the top to "Group resources". (See below)
Resources shared with the group still belong to the original group member, and only s/he can make changes to the original resource. If you want to modify anything in a resource that has been shared by another group member, you will need to upload the resource as a new resource, which essentially makes a copy of the original. Once you have ownership of the resource, you can change it in any way you like.