How do I query for documents that contain a specific value in a map of arrays?

If I have the following set of documents:

{
  "name": "1foo",
  "skus": {
    "1234": ["1234","abcd"],
    "5768": ["5678","efgh"]
  }
},
{
  "name": "2baz",
  "skus": {
    "1111": ["1111","aaaa"],
    "2222": ["2222","bbbb"]
  }
}

What I’d like to be able to do is query for, say, “2baz” given the sku “bbbb”.

If I create an array of objects in the skus, it’s fairly trivial to do, but that feels verbose. If that’s what I need to do, that’s fine, but I’d like to avoid it if I can; I cannot figure out how to get this unwrapped such that I can just query it. An aggregate would be fine, but I haven’t been able to figure out the aggregation either.