This regular expression search for the first opening bracket (
then any character until a closing bracket ) which has to be at the end $
to be matched.
If you replace it with nothing, this results in removing the matching characters between and including the brackets.
This works for (blabla) in the example title text
My text in a title (blabla) and becomes My text in a title
This works NOT for the example title text, where the closing bracket is not at the end of the title.
My Text in a title (blabla) or other text