{
    "collection": [
        {
            "collection": [
                {
                    "rule_id": 190356,
                    "similarity_level": 15
                },
                {
                    "rule_id": 232287,
                    "similarity_level": 25
                }
            ],
            "type": "INCLUDE"
        }
    ]
}

📘
Pixel Lookalike Audiences support a single similarity level of 5.
CRM Lookalike Audiences support a wider range of similarity levels - see: Lookalike Audience Object.

In the above example, the collections property of the outer Audience Targeting Object contains a single Audience Targeting Restrictions Object.

The Audience Targeting Restrictions Object contains a set of lookalike audiences to include. Each lookalike audience is represented by a Lookalike Audience Object.