To limit your search to only individual CWE entry pages, include "inurl:definitions" in your query
Let’s say you want to find a weakness related to Cross-Site Scripting (XSS) to map a CVE Record that deals with XSS. Here is the process you could follow to get to that information using the search feature.
Search for “xss” returns the following:Keyword Search - XSS
Clicking on the first suggestion leads to the page for CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'). Usually, specific keywords will be identified in the first few results, if not the first one. Note that the second search result is CWE-725 which is a CWE Category for OWASP XSS. Remember: never map a vulnerability to a CWE Category