Locate element in multi level array using Groovy

How can I find the userGroupId from a user group type=xyz and userGroupId=5645 from below json using Ruby ?

[
    {
        "userId": "00u2ob4m5",
        "userGroups": [
            {
                "userGroupId": "5645",
                "userGroupType": "abc"
            }
        ]
    },
    {
        "userId": "0e72828b-6417-4371-9588-4cbb55db7e32",
        "userGroups": [
            {
                "userGroupId": "5645",
                "userGroupType": "xyz"
            }
        ]
    },
    {
        "userId": "10592b48-53bf-400e-a417-0079081d1ee0",
        "userGroups": [
            {
                "userGroupId": "7568",
                "userGroupType": "xyz"
            }
        ]
    }
]