I have found a workaround that "sort of" allows me to search within author.
I search over at Fotolia, using their search facilities and when I find the image I want I copy the file # and put that into the Adobe Stock search box.
Thanks for sharing that!
While Adobe hasn't designed the site well for searching beyond the most basic of searches, you CAN search for specific keywords within a given portfolio, you just need to know how to edit the actual URL and what the URL for a search looks like.
Here's an example of a basic URL for a portfolio:
Here's an example of a search for two keywords:
Notice how there is a pattern in the queries of data_field=item
You combine queries with an ampersand (&). So to search for just zombie hands in this particular portfolio, you would enter the portfolio and add "&k=zombie+hands" to the end of the URL, looking like this:
Voila! Searching within a portfolio. The actual coding behind the site allows for more powerful search strings. It's just the interface that doesn't show these options.