This will allow you to save the site:
Once you have multiple saved logins for a site, you will see the field icons show the number of matching sites found. Clicking on the icon will present you with a drop down menu that will show you matching sites:
You can scroll down if more logins are stored than shown. If you do not want to scroll to search, you can begin typing in the username and LastPass will begin to sort through and find matching results.
Clicking the desired login will then autofill the username and password selected.