How to avoid wagtail nested rendering in the admin panel?

let's say I have two models like below:

class Field1Stream(blocks.StreamBlock):
    button1 = AnotherBlock(label="button main")
    button2 = AnotherBlock(label="button secondary")

    class Meta:
        icon = "link"
        required = False
        block_counts = {
            "button1": {"max_num": 1},
            "button2": {"max_num": 1},
        }
        template = "my_template.html"




class NavBar(ClusterableModel, PreviewableMixin):
    ...
    button = StreamField(
        [("field1", Field1Stream()), ],
        use_json_field=True, max_num=1

)

When I use Field1Stream inside NavBar model, it will create a nested structure. If I have a lot of Field1Stream() then it is okay but here I have only one Field1Stream() that's why I don't want to create a nested structure here. With nested I mean like:

How can I avoid it?

When you pass a list to StreamField, such as [("field1", Field1Stream()), ], it will implicitly turn that into a StreamBlock to use as the top-level of the stream. In this case, this results in a StreamBlock embedded in a StreamBlock. To avoid that, pass Field1Stream() directly as the argument to StreamField:

button = StreamField(
    Field1Stream(),
    use_json_field=True, max_num=1
)