Nested labels have disappeared when I removed "parent" label. Where did they go?

Question

I created a label in my Gmail labels and nested other labels under it. When I went to remove the created label this message appeared:

The following labels will be removed from your messages and then deleted. No messages will be deleted.

I went ahead and clicked "remove" thinking only the so-called "parent" or "top" label would be removed and all the other labels nested under it would be returned to the top level, but alas they disappeared too. What happened to the nested labels? Also how can I un-nest a label, to stand alone as it did before nested?

Answer 1

As you've discovered, removing a parent label removes all of its child labels as well. This is a design decision and I'll wager that they researched whether more people would expect the children to be removed or moved up one level to the top. I also expect that it's much easier to code. (Can you imagine how complex it would be to manage a four-level deep nested label when you delete a parent at level two?) The warning message could probably be clearer.

As to your second question, un-nesting a label:

1. Go to "Settings"
2. Choose the "Labels" tab
3. Find the label you want to "un-nest". Click edit
4. Uncheck the "Nest label under:" checkbox (see screen shot below)
5. Click "Save"

Answer 2

Labels are a bit like folder. You can see it clearly if you acces your gmail account via imap.

A label Level2 nested in Level1 is identified as Level1/Level2.

An email in Level1/Level2, is also in All mail and Inbox if it hasn't been archived.

If you remove Level1 you loose Level1/Level2 but your emails still are in All mail and in Inbox (if not archived)

If the 2nd level label was applied from a filter, simply recreate the filter and tick the box to apply to matching conversations.