[{"testname":"process","jobId":"job1","vt_cond":"cond1","testData":[{"chip":"c1","name":"block1"},{"chip":"c1","name":"block1"},{"chip":"c1","name":"block2"},{"chip":"c1","name":"block3"}]}]

db.collection.aggregate([{$match:{"jobId":"job1","testData.name":"block3"}},{"$addFields":{"testData":{"$filter":{"input":"$testData","as":"t","cond":{$eq:["$$t.name","block3"]}}}}}])