Populate "Artist" from a portion of TITLE

Support
1

I read the topic "ACTION: How to pull part of Title into Artist field" but I'm still unsure.

I have track titles like: Pretty Thing { Bo Diddley }
or like: Dust My Broom ( Elmore James )

I want to use Tag to Tag to populate the track artist field from the track title.
In Tag to Tag I would choose ARTIST in field because that's the field I want to populate but how do I tell it in the Format String field to pull a portion of the track title tag?

2

I would use an action of the type "Guess value"
Source: %title%
Target;: %title% (%artist%)