When searching using PatSnap it is possible to search using classification codes where this can be done by either typing into the search bars in the classification code options within Advanced search or by using the refine options when a search has been completed. You can find more about the different classification codes here: What Are The Different Classification Codes?
It is useful to use classification codes when searching because it allows you to focus your search on a particular area of technology. This is particularly advantageous since it will enable you to get a strong idea of what is already out there in terms of innovation for this area as well as being able to predict the future progress in this area. From this information, you will be able to see possible whitespace opportunities so that you get a good idea whether it is worth pursuing work in this area.