re = /TABLEXY1(\(([^()]|(?1))*\))/
str = 'TABLEXY1((INITIALPARAM2*117.3/MADAD(2)),INITIALPARAM1+1)*PARAM2/100*(TABLE12(INITIALPARAM3)*PARAM3-(TABLE12(INITIALPARAM4)*PARAM4)'
# Print the match result
str.scan(re) do |match|
puts match.to_s
end
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 Ruby, please visit: http://ruby-doc.org/core-2.2.0/Regexp.html