[{_id:"61cae5daf5bfbebd7cf748ee",title:"category 1",SubCats:[{_id:"61cae5daf5bfbebd7cf748ef",name:"subcat 1",image:"/assets/images/vr-box-6203301_1920.jpg"},{_id:"61cae5daf5bfbebd7cf748fb",name:"subcat 2",image:"/assets/images/galaxy-s20_highlights_kv_00.jpg"}]}]

db.collection.update({"SubCats._id":"61cae5daf5bfbebd7cf748ef"},{"$pull":{SubCats:{_id:"61cae5daf5bfbebd7cf748ef"}}},{"multi":true})