using Feeds Xpath Parser to import RSS feeds
You have to fully understand the XPath queries logic to use the parser. It's very powerful once you get it, but it needs a bit of practice.

Here is a good starting page : http://www.w3schools.com/xpath/

Note that you have two parts in the UI for the queries : 


One to set the context, which is the element all further queries will be run from
One for each field


The context element depends on your document and the logic of the data inside. Usually, you set the context each 'entity' or node is saved in, and then query fields or attributes for the different fields.

For example, if you have a 'Thing' entity like this :

&lt;Thing&gt;
&lt;id&gt;1&lt;/id&gt;
&lt;name&gt;Name One&lt;/name&gt;
&lt;/Thing&gt;
&lt;Thing&gt;
&lt;id&gt;2&lt;/id&gt;
&lt;name&gt;Name Two&lt;/name&gt;
&lt;/Thing&gt;


... you would set the context to /Thing and then each field query to name and id. You also have a syntax to query attributes.

Also, be aware Feeds is only compatible with XPath 1.0 syntax.