Database

[{"_id":ObjectId("5ed4bcda3c6f0e386b9bee92"),"parsedText":[{"paragraphs":[[{"lineText":"E x h i b i t 1 0 . 2","startT":[10.00648158191587],"endT":[10.00648158191587]}],[{"lineText":"VENDOR Afdfj AGREEMENT","startT":[10.00648158191587],"endT":[10.00648158191587]}]]},{"paragraphs":[[{"lineText":"CONFIDENTIALITY","startT":[10.00648158191587,NumberInt(0),NumberInt(0),10.00648158191587,34.00538853510875,711.4527903321338],"endT":[10.00648158191587,NumberInt(0),NumberInt(0),10.00648158191587,70.0377305857611,711.4527903321338]}],[{"lineText":"Tesijtiosje","startT":[10.00648158191587],"endT":[10.00648158191587,]},{"lineText":"wkdfskdjfksdlfkjlsdjf","startT":[10.00648158191587,],"endT":[10.00648158191587,]},{"lineText":"asdjiasjdoasid","startT":[10.00648158191587,],"endT":[10.00648158191587,]}],]}]}]

Query

db.collection.aggregate([{$unwind:"$parsedText"},{$unwind:"$parsedText.paragraphs"},{$addFields:{parsedText:{$arrayElemAt:["$parsedText.paragraphs",0]}}},{$group:{_id:"$_id",parsedText:{$push:"$parsedText.lineText"}}},])

Result