Database
[{"_id":"61cab38891152daf9387c0c7","name":"dummy","company_email":"abc@mailinator.com","brief_msg":"Cillum sed est prae","similar_case_ids":[],"answer_id":["61cab38891152daf9387c0c9"],"pros_cons":[{"vendor_name":"xyzlab","score":[{"question_id":"61c5b47198b2c5bbf9f6471c","title":"Vendor F","confident_score":80,"text":"text1","_id":"61cac505caeeeb3cec78bf0f"},{"question_id":"61c5b47198b2c5bbf9f6471c","title":"Vendor FFF","confident_score":40,"text":"text1","_id":"61cac505caeeeb3cec78bf10"}]},{"vendor_name":"abclab","score":[{"question_id":"61c5b47198b2c5bbf9f6471c","title":"Vendor B","confident_score":50,"text":"text1","_id":"61cac505caeeeb3cec78bf16"},{"question_id":"61c5b47198b2c5bbf9f6471c","title":"Vendor BB","confident_score":60,"text":"text1","_id":"61cac505caeeeb3cec78bf17"}]}]}]
Query
db.collection.aggregate([{$match:{_id:"61cab38891152daf9387c0c7"}},{$unwind:{path:"$pros_cons"}},{$project:{_id:0,vendor_name:"$pros_cons.vendor_name",totalScore:{$reduce:{input:"$pros_cons.score",initialValue:0,in:{$sum:["$$value","$$this.confident_score"]}}}}}])