How to select all children?

[Spliff]

No problem, cnewtonne: "their degree of organization will rise spectacularly, by masking non-pertinent "details" info whenever not needed (yet)." - this being said, "by n levels" is not that helpful anymore, once n >= 3 (since n is counted from the current level down): it's about avoiding clutter while thinking about what you've got, and what you should add, amend, change, think over...*

And for purely organizational / business means, it helps to identify / correctly maintain customer / goods / etc data, even and especially if you switch between entering data in UR, and retrieving data by SQL.

*=I recommend "show 1/2 level" in particular (beyond for drilling down of course) for drilling UP, i.e. when you will have been within SOME details (spread over possibly even more than one level further down, and possibly in more than just one sub-tree further down), and then "go" up again: In this situation, "show 1 (or, rarer, 2) level", triggered from your original starting point again, is wonderful (and neither to be mixed up with (collapse by) {left} (arrow) nor with "collapse tree") - especially since "going up again by {left} will remember the expansion state "further down", which is NOT wanted in these situations:

Use "Show 1 level" even more upward, than downward, and you'll get its tremendous interest even faster...