You can now define up to 5 saved searches in your profile.
The searches then run periodically in the background, and you will get notified when new posts occur.
It’s a bit clunky to operate, but…
Create a search with whatever parameters you wish, then copy the contents of the search bar (highlighted):
Go to your profile, then to “Saved Searches” and copy paste that string into one of the 5 text boxes.
Click on “Save Changes” and you’re done.