Database
db={"assessmentNotice":[{"_id":{"$oid":"653d5269bddbd13af40c339a"},"referenceNumber":"220000007131","status":"UNMAPPED"}],"measurementNotice":[{"_id":{"$oid":"653d5268bddbd13af40c3396"},"data":{"referenceNumber":"220000003003"}},{"_id":{"$oid":"653d5269bddbd13af40c3399"},"data":{"referenceNumber":"220000007131"}}]}
Query
db.assessmentNotice.aggregate([{$lookup:{from:"measurementNotice",let:{ref_number:"$data.referenceNumber"},pipeline:[{$match:{$expr:{$eq:["$$ref_number","$referenceNumber"]}}}],as:"lookup"}}])