sort products

Go to Admin Panel and click on "Configuration" menu then click on Taxonomies link on the right side panel.

Click on any of the edit icon of the taxonomies, which has the taxon you wish to sort the products position in.

Now, right click on the taxon you wish to change the products positions in it. You'll see a menu called: "Sort Products", click on it.

Here, you'll see a list of products which are in associated with the taxon, and can drag and drop them to the specific position according to your requirements.

Once you change the positions after sorting products under a taxon, you will see button to save the sorted positions:

When you'll click on "Save the sorted position" button. Your products position with in that taxon will be updated.