Similar to jQuery .closest() but traversing descendants?

Question

Is there a function similar to jQuery .closest() but for traversing descendants and returning only closest ones?

I know that there is

Answer 1

If by "closest" descendant you mean the first child then you can do:

$('#foo').find(':first');

Or:

$('#foo').children().first();

Or, to look for the first occurrence of a specific element, you could do:

$('#foo').find('.whatever').first();

Or:

$('#foo').find('.whatever:first');

Really though, we need a solid definition of what "closest descendant" means.

E.g.

Which would $('#foo').closestDescendent('span') return?