[{"data":{"category":[{"name":"HELLO","subcategory":["EDUCATION","ART",]},{"name":"HELLO","subcategory":["GG","ART",]},{"name":"HELLO","subcategory":["EDUCATION","SHORE",]}]}},{"data":{"category":[{"name":"HELLO","subcategory":["EDUCATION","HELLO",]}]}},{"data":{"category":[{"name":"HELLO","subcategory":["GG","ART",]}]}}]

db.collection.update({"data.category.subcategory":"EDUCATION"},[{"$set":{"data.category":{$map:{input:"$data.category",in:{$mergeObjects:["$$this",{subcategory:{$map:{input:"$$this.subcategory",in:{$cond:{if:{$eq:["$$this","EDUCATION"]},then:"SPORTS",else:"$$this"}}}}}]}}}}}],{multi:true})