Redis – How to Create a Hash Within a Hash

I want to create this type of a structure in redis: (its basically json data)

{
    "id": "0001",
    "name":"widget ABC",
    "model": "model123",
    "service":"standard",
    "admin_password": 82616416,
    "r1":
        {
            "extid":"50000",
            "password":"test123",
        },
    "r2":
        {
            "ext":"30000",
            "password":"test123",
        },
}

What I've tried so far:

I've tried to create a hash without the "sub" hashes, just to make sure I have the basics down pat.
So here's what I started with from the redis-cli:

HMSET widget:1 id 0001 name 'widget ABC' model 'model123' service standard admin_password 82616416
HMSET widget:2 id 0002 name 'widget ABC' model 'model123' service standard admin_password 12341234

That seems to work. I can see that I have 2 "records" of widget data in a widget collection.

But my attempt to create a record with the r1 data fails.

This is what I tried:

HMSET widget:3 id 0002 name 'widget ABC' model 'model123' service standard admin_password 12341234 r1{extid 50000} 

This creates a hash key "r1{extid" with a hash value of "50000}"

Any suggestions would be appreciated. I think my problem is my lingo. I just don't know enough about the redis syntax to know what words to use in my google search.

Perhaps I just have to "flatten" the data like so:

HMSET widget:3 id 0002 name 'widget ABC' model 'model123' service standard admin_password 12341234 r1_extid 50000 r1_password test123 r2_extid 30000 r2_password test123

Thanks.