How to exclude group from deleting

Question

i have this regex:

(%)([[:punct:]&[:alnum:]& ]{1,1})(%)

https://regex101.com/r/FUmP8G/1

and it's deleting whole 3 groups, how to keep 2nd group for searching but exclude it from deleting?

For example:

%@%

Result:

@

Answer 1

try this pattern /(?<=[%])([[:punct:]&[:alnum:]& ]{1,1})(?<![%])/

here a demo