It would be useful sometimes to be able to filter on multiple strings in the Selections(12) section. For example, if you have files like so:
A filename with a string AAAA
A filename with a string BBBB
A filename with a string CCCC
A filename with a string DDDD
Then in the Selections(12) field you could do something filter: AAAA+CCCC (or maybe AAAA|CCCC) to only change files with those 2 strings and ignore the other 2 files. For large folders or files across many folders, it requires a lot of CTRL-clicking to select only the files you want to change.