Expand/collapse track folders - can you?

Hi Is there a way in one click somewhere collapse all children to a track folder? Both in TCP and MCP. That it's doing the same as opening Track manager clicking all the children one by one. To preserve workspace and quickly do that would be very handy. And sometimes newly created tracks end up within a folder if intending as a new track outside etc. This can be avoided if hiding children. Otherwise Trackmanager and Trackfolders are really well implemented. Thanks.

Yes, it's in the manual. I'm not in front of REAPER at the moment, but you just click on the left somewhere to expand or collapse them. I think there are key modifiers too, to do cleverer stuff with them... Sorry if that's a bit vague. >

What was the verdict? How do you collapse all the parent folders at once? Does it work also to expand them as well?

A picture paints a thousand words...or something.

Can tracks in the mix window also be collapsed? I would find it very useful to collapse all my rhythm tracks together and expand them only when I need to adjust a level or plugin, but I seem to only be able to condense folders in the arrange window/TCP.