Database
[{"storeNum":"71249","publicHealthUnit":"222","restrictionTracker":[{"dailyCapRunningTotal":30,"weeklyCapRUnningTotal":15},{"dailyCapRunningTotal":20,"weeklyCapRUnningTotal":10}]}]
Query
db.collection.update({},{$set:{"restrictionTracker.$[].dailyCapRunningTotal":0}},{many:true})