SameperiodLastYear Visualization

In case of SameperiodLastYear function its taking input of metric column and date, but during the visualization if user remove the date filed. it showing error. If this function start supporting at attribute, using existing inputs it will more usable. Secondly if it support date hierarchy, it will be wonderful. Example: if i want to analysis last year sale of any channel/region/state/city without adding date in visualization.