[{"_id":ObjectId("60a2c0621e5f043b735e36ef"),"car_id":78,"terminal":"JFK","gists":["A","M","C","D","Q","J","F"]},{"_id":ObjectId("60a2c0621e5f043b735e36f0"),"car_id":79,"terminal":"LAX","gists":["A","M","C","D","Q","J","F","A"]},{"_id":ObjectId("60a2c0621e5f043b735e36f1"),"car_id":80,"terminal":"ORD","gists":["A","M","N","L","Q","A","O"]},{"_id":ObjectId("60a2c0621e5f043b735e36f2"),"car_id":81,"terminal":"MIA","gists":["X","L","X","D","Q","E","E"]},{"_id":ObjectId("60a2c0621e5f043b735e36f3"),"car_id":82,"terminal":"ORD","gists":["H","H","C","D","A","B","C"]},{"_id":ObjectId("60a2c0621e5f043b735e36f4"),"car_id":83,"terminal":"JFK","gists":["X","Q","K","D","C","J","F"]},]

db.collection.aggregate([{$match:{$expr:{$gt:[{$size:{$filter:{input:"$gists",cond:{$eq:["$$this","A"]}}}},1]}}},{$group:{_id:null,car_id:{$push:"$car_id"}}}])