How to share context between sub-groups?

[infn-ke]

How can I share context between sub-groups? I tried making use of pass_context, but it looks like I'm only able to pass context from root cli (parent) to sub-group and not between sub-groups. E.g. snippet code

import click

@click.group()
@click.pass_context
def cli(ctx):
    ctx.ensure_object(dict)
    ctx.obj["shared"] = {}


@click.group()
@click.pass_context
def group1(ctx):
    pass


@click.group()
@click.pass_context
def group2(ctx):
    pass


@group1.command()
@click.pass_context
def foo(ctx):
    ctx.obj["shared"]["foo"] = "foo inserted a value"


@group2.command()
@click.pass_context
def bar(ctx):
    c = ctx.obj["shared"]["foo"]
    click.echo(f"{c}")