If you want to analyze all items in your project where the value of a field matches a string fragment, you can use wildcard characters with the EqualTo and NotEqualTo operators on the Filter Builder. The ? wildcard takes the place of a single character. The * wildcard takes the place of multiple characters.
For example, if searching for all task names containing "legal" you can enter the value "legal". If you only wanted task names that end in the word "review" and a single number, you would enter the value "* review ?" This filter would retrieve "Design Review 1" and "Design Review 2" and "Legal Review 1" but not "Design Review 10".