Its not missing, the slides field group is in a plugin:
'blueprints' => [
// HERO FIELDS
'slides' => __DIR__ . '/blueprints/fields/slides.yml',
]
And yes, slides.yml looks like this, its just a field group:
type: group
fields:
heroslidesfield:
label: Hero Slides
type: files
layout: cards
width: 3/4
options: query
query: page.images
image:
cover: true
ratio: 16/9
size: tiny
when:
herotype: slides
showslidecaptions:
label: Show Slide Captions?
type: toggle
width: 1/4
when:
herotype: slides
I got it to work but it looks like you need to redeclare the extend with another group, and put the changes in there:
# HERO
hero:
extends: tabs/hero
columns:
left:
width: 2/3
sections:
herocontent:
type: fields
fields:
herotypeheading:
label: Hero Type
type: headline
slideshero:
extends: fields/homeslides