Adobe Analytics recently released Folders on the Workspace screen, which is a useful way of organising projects.
A similar feature in the Target UI, which is basically Folders for activities would be a great feature. The existing filters are somewhat useful but it would be helpful to have the ability to create and nest folders so activities can be organised by internal things like product, brand, stakeholder group, financial year, quarter etc.
Workspaces is not the right solution for this as we use them for clientside, serverside, sandbox etc. We already use a descriptive naming convention for our activities but dozens of them are getting difficult to manage.