You can do it with folder structure or with field. And the data for the map may be a data source.
With folder, you have /Showrooms, then /Showrooms/Service and /Showrooms/Sales. The 3 button will control the folder path of the data source to show which folder will be used to list all showrooms.
With field like a checkbox or radio button for "Service" and "Sales". Then the button click will change the data source WHERE condition to RoomType = "Service", RoomType = "Sales", RoomType = "Service" or "Sales".