mongodb query using $in for list of lists

Question

I have a document as:

{
    'name':'XYZ',
    'address':'Street 21',
    'phone': {
        'home': [123456, 456123]
    },
    'qualification': {
        'primary': [
            ['AB','75'],
            ['CD','80'],
            ['EF','50']
        ]
    }
}

Simple query would be like:

n = collection.find({'name':'XYZ'})

I can fetch documents using a list on the 'phone.home' subdocument key like this:

list1 = [123456]
n = collection.find({'phone.home':{'$in': list1}})

I am stuck on how to query the collection using the qualification key. Suppose I have either 'AB' or '75' (only one of them at a time), I am not able to make up query, e.g I only have the following list1:

list1 = ['AB']

n = collection.find({'qualification.primary':{'$in':list1}})

This definitely is not giving me the desired result. Any guidance will be appreciated!

Answer 1

Use $elemMatch two times query as :

db.collectionName.find(
    {
      "qualification.primary":{ "$elemMatch": { "$elemMatch":{ "$in": ["AB"] }}}
    },
    { "qualification.primary.$":1 }
)