The standard way to export data from X-Cart is using the tool described here.
However, there can be cases when you need to export products partially, which is impossible with the regular export procedure. To do so, you need to use the export tool on the product listing page.
To export products:
Select the products you need to export on the products listing page of your store's Admin area (Catalog > Products).
You can do this manually or use the filters in the search bar described here.
Click the "Export selected" button at the bottom of the page.
The menu will expand.
Select the format and click to start the export. The file will be downloaded automatically.
The product listing page also allows exporting of the product catalog as a whole. For this purpose, do not select products and use the "Export all" button at the bottom of the page.