Steps to reproduce:

1. Log in to back office.
2. Go to Admin / Product catalog / Products.
3. Add few products.
4. Expand 'Sort by' dropdown.
5. Type product name in search input.
6. Click on search button.

Actual result:

See attached screenshots.

Search functionality in 'Sort by' dropdown does not work.

Expected result:

Search functionality works properly.

Q: Do we need this search input in 'Sort by' dropdown?

NOTE:

There are discrepancies between two versions 4.1 and 4.2 with available options in 'Sort by' dropdown.

Please take a look on screenshots with names 4.1 and 4.2.