Hopefully the Apple developers will consider this for a future version.
In the meantime, if you want to have a list of fav samples in your project folder which have been loaded into an Ultrabeat kit,
Save as... and make sure that you have Include Assets ticked and Copy Ultrabeat samples to project folder ticked too.
In the Media Window, go to Browser tab and navigate to your project folder. In the project folder you'll see an "Ultrabeat samples" folder. Open it and you can see all the samples in your UB kit.
Another option would be to create a folder in a finder window. Put your samples in the folder and switch between Logic and the folder (or have both on screen at the same time) so you drag and drop and see the folders contents. Not ideal, but useful if you copy the folder to your project folder.