collection (Structured Query)

Specifies what collections to look in for documents. If no collection query is included in the query, all collections will be searched.

{"collection": "books"}

<collection>books</collection>

To search in multiple collections, provide a list of collections instead of just one as a string:

{"collection": ["books", "magazines"]}

<collection>
    <value>books</value>
    <value>magazines</value>
</collection>