db={"Workflow":[{id:1,name:"workflow",status:"started",createdDate:"2021-02-10",tasks:[{taskId:"task1",value:"new"},{taskId:"task2",value:"started"},{taskId:"task3",value:"completed"}]},{id:2,name:"workflow",status:"started",createdDate:"2021-02-10",tasks:[{taskId:"task1",value:"new",descri:"bsdcbashjdc"},{taskId:"task2",value:"started"},{taskId:"task3",value:"completed"}]},{id:3,name:"workflow",status:"started",createdDate:"2021-02-10",tasks:[{taskId:"task1",value:"new"},{taskId:"task2",value:"started"},{taskId:"task3",value:"completed"}]}]}

db.Workflow.aggregate([{$match:{}},{$unwind:"$tasks"},{"$addFields":{"workflow":"$$ROOT"}},{"$project":{workflowTask:"$tasks",workflow:"$workflow"}},{$set:{"workflowTask.workflow":"$workflow"}},{$unset:["workflowTask.workflow.tasks","workflow","_id"]},{$facet:{data:[{$skip:0},{$limit:30},],count:[{$group:{_id:null,total:{$sum:1}}},],}}])