Nested Wagtail StreamBlocks for nested sidebar content

models.py

from wagtail.core.models import Page
from wagtail.core import blocks
from wagtail.images.blocks import ImageChooserBlock

class NestedSidebarContent(blocks.StructBlock):
    sidebar_alignment = blocks.ChoiceBlock(choices=(
        ("left", "Left"),
        ("right", "Right"),
    ))
    main_content2 = blocks.StreamBlock([
        ("richtext", blocks.RichTextBlock()),
        ("image", ImageChooserBlock()),
    ])
    sidebar_content2 = blocks.StreamBlock([
        ("richtext", blocks.RichTextBlock()),
        ("image", ImageChooserBlock()),
    ])


class SidebarBlock(blocks.StructBlock):
    align = blocks.ChoiceBlock(choices=(
        ("left", "Left"),
        ("right", "Right"),
    ))

    sidebar_content = blocks.StreamBlock([
        ("richtext", blocks.RichTextBlock()),
        ("image", ImageChooserBlock()),
    ])
    full_width_content = blocks.StreamBlock([
        ("richtext", blocks.RichTextBlock()),
        ("image", ImageChooserBlock()),
        ("nested_sidebar", NestedSidebarContent())
    ])


class FullWidthBlock(blocks.StructBlock):
    full_width_content = blocks.StreamBlock([
        ("richtext", blocks.RichTextBlock()),
        ("image", ImageChooserBlock()),
        ("nested_sidebar", NestedSidebarContent())
    ])


class HomePage(Page):
    # ... 
    body = StreamField([
            ("sidebar_layout", SidebarBlock()),
            ("full_width_layout", FullWidthBlock()),
        ],
        blank=True,
        null=True,
    )