ArcGIS Pro 2.6 API Reference Guide
FilePath Property
Example 

ArcGIS.Desktop.Catalog Namespace > SaveItemDialog Class : FilePath Property
Gets the name of the file that will be saved
Syntax
public string FilePath {get;}
Public ReadOnly Property FilePath As String
Remarks

The FilePath property is set as a result of browsing in the dialog box to a location and providing a name for the new file that will be created. You can get the property's value after dismissing the Browse dialog box.

The value returned from the FilePath property is the full path to the file and its file name. The path is determined based on the location currently being viewed in the Browse dialog, which is extracted from the breadcrumb control. The file name includes the file extension that was specified in the Name text box or was defined as the default file extension for the dialog box.

Example
SaveItemDialog saveMapFileDialog = new SaveItemDialog()
{
  Title = "Save Map File",
  InitialLocation = @"C:\Data\NewYork\Counties\Maps",
  DefaultExt = @"mapx",
  Filter = ItemFilters.maps_all,
  OverwritePrompt = true
};
bool? result = saveMapFileDialog.ShowDialog();

if (result == true)
{
  ArcGIS.Desktop.Framework.Dialogs.MessageBox.Show("Returned file name: " + saveMapFileDialog.FilePath);
}
Requirements

Target Platforms: Windows 10, Windows 8.1, Windows 7

See Also

Reference

SaveItemDialog Class
SaveItemDialog Members