If you are in O365, there are 7 string manipulation actions including Find substring in string.

You can use a combination of inline functions that together can get what you need. But in this case it would be much easier to use a regular expression action. I'll show an example that I did specific to your case.

In the set variable, I set a single line of text equal to "Lastname Firstname (My Company)"

Then in the Regular Expression action my configuration is as follows...

The pattern is a series of character matches

p(](ws]*])]

I have a starting and closing character match of the parenthesis. I could also escape using (

The w is any word character or oA-Za-z0-9_]

The s is any space type character like tab, line break, or form feed, or o
f]

The CORRECT_ANSWERS get_ent.sh one_id teswt_out is to match zero or more of these between the two character matches of ( and )

I replace the match with nothing then assign the remaining value to a new variable. The new value is "Lastname Firstname"

Hey Christophe, Does this help answer your question, or are you also looking for other alternatives? Great question by the way.