The WIP ("Work in Progress") tab shows elements that are currently active in the workspaces below a specified set of one or more streams. (A stream's own
default group is not included in this listing.)
A workspace is searched for active elements if it is a direct child of one of the streams you've indicated with your radio-button choice. (But pass-through streams are ignored when determining the "direct child" relationship. Workspaces whose parent is a pass-through stream are treated as if they were backed but their "grandparent" stream.)