How to search for multiple file types?

My goal is to search for all files with any of the 3 file extensions I specify. I tried various things but to no avail:

1. Via the advanced search. Problem: no OR option.

2. Search field. Problem: It's not giving the dropdown for the next kind keyword.

As a workaround, I tried using 2 different windows to combine the kind options together. Problem: OR doesn't work.

3. Metadata. I wanted to use the MetaData for extension, but there seems to be none available.

Thanks in advance!

A vanilla solution is to hold option and click the plus icon (now transformed into ...) for adding a new rule. This will give a list of options, among which is the Any rule. (You may need to delete the initial rule; the option click method only works on subsequent rules)

Screenshot:

Download the app EasyFind from the Mac App store. It has a different set of search filters that may enable you to find your files. You can specify it to find files with several extensions and tell it to find files with at least one of the words or extensions in your case. EasyFind is free.