Database
[{"_id":"622226d319517e83e8ed6151","Name":"test1","Description":"","Items":[{"_id":"622226d319517e83e8ed614e","Name":"test-item","Description":"","Process":[{"Name":"Step1"},{"Name":"Step2"}],"Items":[{"_id":"622226d319517e83e8ed614f","Name":"test-subItem1","Description":"","Process":[{"Name":"StepSub1"},{"Name":"StepSub2"},{"Name":"StepSub3"}],"Items":[]},{"_id":"622226d319517e83e8ed6150","Name":"test-subItem2","Description":"","Process":[{"Name":"StepSub4"},{"Name":"StepSub5"},{"Name":"StepSub6"}],"Items":[]}]}]}]
Query
db.collection.update({},{$unset:{"Items.$[].Items.$[].Process":1,"Items.$[].Process":1}})