G'day Rolf,

My settings (top of RAT page):

Current View Mode is Full Thread, switch to Root and Node, Minimal Nod
+es or Node Ancestors
[download]

There's been some activity between posting this morning ... long work day ... logging back in this evening.

Now: 5 "Re^9" entries; 2 have "+/-"; 1st "+/-" gave "Re^10"; 2nd "+/-" gave all "Re^10" to "Re^13" with one click.

That's still fiddly when a quick top-level view is wanted; however, and with reference to your "second reply", setting "maximum depth" to zero gave a full hierarchy of all nodes in all threads: I'll stick with that as it seems to do what I want. Thanks.