Please check the 4.3.0 release notes!

[Rebecca Breu]

The split layer into local selection masks has gone out in the 4.2.9
release. It's been mentioned in the release notes of 4.2.9 as well.

On Mon, 04 May 2020 16:21:26 +0200
Boudewijn Rempt <boud at valdyas.org> wrote:

> Everyone who has done work on Krita that wasn't backported to 4.2.9,
> please check https://krita.org/en/krita-4-3-release-notes/ and if we
> have forgotten something, reply to this mail with a short paragraph
> explaining the new feature or improvement!