Hello Suhas - thanks for your question and welcome to the Qlik Community.
Please take a look at:
- Qlik Sense - Variables Interface (video)
- Parts 1 and 2 of Introduction to Set Analysis (video) - Part 1
- Parts 1 and 2 of Power of Qlik Script - Reshaping Data with Crosstable (video)
in the New to Qlik Sense Videos - page
"Complex Logic" - is subjective - so we would need a bit more information on what it is you wish to achieve to point you to more specific areas.
Thank you Sangram and Blaraj - for your continued support and contribution.
Please mark the appropriate replies as CORRECT / HELPFUL so our team and other members know that your question(s) has been answered to your satisfaction.