[{"_id":"6021d4e8de525e00bb3623f1","addonGroups":[{"_id":"6021d474143dbb00da601e6a","name":"Additions","addons":[{"name":"Nike\t珍珠",},{"name":"Adidas\t椰果",},]}],}]

db.collection.aggregate([{$set:{addonGroups:{$map:{input:"$addonGroups",as:"addonGroup",in:{"$mergeObjects":["$$addonGroup",{"addons":{$map:{input:"$$addonGroup.addons",as:"addon",in:{$mergeObjects:["$$addon",{"name":{$replaceAll:{input:"$$addon.name",find:"\t",replacement:" "}}}]}}}}]}}}}}])