If you click on a bundle in the store, there's a link to [ Show included packages ] and clicking on that pops up a window with blue links for each original package, then clicking on one of those gets you a description of which Paizo products are included.
Since going through those one at a time is really tedious, what I suggest is to do a forum post search in the
HLC PF1 forum for the name of the book you want. For example, doing a search for "Numeria, Land of Fallen Stars" with Show Posts selected turns up the announcement for the version of the data files that added the content, which says it's in original Pathfinder Campaign Setting #12. After that, it doesn't take too long on the store to confirm that it's now in Campaign Setting Bundle #2 PF1.
Hope that helps!