# If you'd like to omit non-matching lines from the result; add ';d' to the end of the expression.
sed -E 's/\((.*)\).*?\(?\1\)?/(\1)/gm;t' <<< "Chiaro Gallo (blabla) (blabla)
Ricard Michaeln ()
Marco Liu (Hong Kong Stock Co Ltd) Hong Kong Stock Co Ltd
Rafiq (Kkska Traning Co (p) Ltd) Kkska Traning Co (p) Ltd
"
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for SED, please visit: https://www.gnu.org/software/sed/manual/html_node/The-_0022s_0022-Command.html