Can you create a new library with those titles? If so, then you could import your library with duplicates settings as “title” only (in preferences/duplicates) with discard duplicates ON into the title only library and to discard them into a new library, which would essentially be those that were the titles you started with?
So from the titles library – file>import (on a PC) – import endnote library, with setting for duplicates as in attached image, and then find your original library and import. This time you want to open and save the duplicates as a new subset.
Alternatively (and this will retain any endnote record numbers of your original library) -
Make a copy of your original library and create a new library of the titles only set. After ensuring your duplicate settings in preferences only look at the fields in your CVS imported library – this time, import without discarding duplicates, the titles only into the library copy (Doing this on a copy is so, if things go pear shaped, you can go back to the original library). Create a group – like Literature review. Now run the duplicate search, close it. You should be left with the new set highlighted and the original set not highlighted. from references hide those highlighted. This should leave you with your original set that matched your titles selected. select them all and drag them into the group you created. Do the duplicate search again, and close and now delete the selected set (which should be titles only.) and you now have the group of titles you want to use in your lit review in a group, still in the context of your whole library.
But next time, why not select them and move them to a group, in the first place rather than export and decide?
