Either you can put a button widget on page choose event as Close page that will take you to the previous page used by current user session , else if its microflow put an a Close Page activity on that.
If its only for take user to previous page use simple button widget with close page event or use a nano flow to do. A microflow call really not necessary to do this unless if you want to execute some logic on back button
Hope this helps.
to further explain on Sathya’s information.
Mendix opens up pages on top of eachother. The close page function closes the current page, resulting in the previous page being shown. If you use a close page action before opening a new page, that page is removed from your stack of pages.