By default, most plots will query all location-interval pairs. In order to plot a particular set of location-interval pairs you may click on the List button in the query tab and then either pick location-interval pairs one-by-one or select a pre-defined Location Group. Location Groups are stored within the EnviroInsite document and are available for selection from plot objects within any view.
You may add or remove Location Groups by selecting Edit -> Groups -> Locations. That will open the following dialog box.