Database

[{"_id":ObjectId("60ae0b29ab282518443c7ac5"),"details":[{"label":"Asset title","value":"S1",},{"label":"Total Cost","value":"250",},{"label":"Possession Status","value":"Available",},{"label":"Estimated Monthly Rent","value":"15.5",}]},{"_id":ObjectId("60ae0b29ab282518443c7ac8"),"details":[{"label":"Asset title","value":"S2",},{"label":"Total Cost","value":"455.5",},{"label":"Possession Status","value":"Available",},{"label":"Estimated Monthly Rent","value":"30",}]}]

Query

db.collection.aggregate([{"$project":{"data":{"$map":{"input":"$details","as":"val","in":{$cond:[{$in:["$$val.label",["Total Cost","Estimated Monthly Rent"]]},{label:"$$val.label",value:{$toDouble:"$$val.value"}},"$$val"]}}}}}])

Result