It seems like it should be possible, but the way the helper methods are structured I can't see an easy way of constructing that query directly.
The only way I could recreate the desired query is by doing variations of the following:
var queryDocument = QueryDocument.Parse("{\"$in\" : [\"Hamster\"]}");
var nestedQueryDocument = Query.ElemMatch("Field", new QueryDocument(queryDocument));
Creates the following output
{
"Field" : { "$elemMatch" : { "$in" : ["Hamster"]}}
}
Not the most elegant of solutions though.