Bathymetry editor in GUI v3.2

Hello, I am trying to use the bathymetry editor in v3.2 of the GUI to coarsen a bath file. I can open the w2_con file in the GUI. However, when I click on the bathymetry button, the program states "file not found". Does the bath file need to be located in a specific directory? When I try to open the bath file, I am not given the option of locating the file. Is this normal? Thanks, Vickie Singleton