How do I find distributors for high-end stores like Macy's, Nordstrom's, etc.?

What we suggest that you do is do some research on your competitors (companies that are selling your niche) and see what their top selling brands/ products are. Once you figure that out you should be able to tell who their distributors are.

Also, as a drop shipper 1) you don't want to sell a niche that already has brand loyalty (EX - trying to sell tablets is difficult because people immediately think of buying an Apple product because they trust the brand). 2) Some high end suppliers (probably like suppliers for Nordstroms) have exclusive deals with individual retailers and thus won't be suppliers for other retailers.