Currently we are matching the Content of http Response with value in Content Analysis,
we have a scenario where we need to compare the content (greater then or less then) and provide the content match as True or False,
You should be able to get what you want using Website Input by using an input that extracts that data along with a search the ensures the value is what you expect. Here is what I am thinking:
Create an input using the included wizard against the URL with the given XML file. Set the selector to "total-hosts". Confirm that the extraction is working as intended by clicking "Preview Output".
Create a saved search that looks at the output created by the input you just made. You ought to be able to setup the logic such that it will alert you when "total-hosts" is 3 or less (something like "... | search match <= 3"