How to filter title with multiple conditions

How can if filter for different words in title. E. g. I wan to filter for the all test cases with “O2C” in title and with “NC” in title.

So you want to have all TCs in the test plan that have “O2C” or “NC” in the title?
You can just add 2 filter queries to the test plan, one filtering for “O2C” and one for “NC” - the union of the TCs found by both queries will be in the test plan.

Best regards,
Alex