Customize Filter in Quotation Trend

Hi, may i ask some question about how to customize the filter like the filter that using select button in quotation trends that show in the picture as below? can give some guide to me? i still an newbie so hope can get some detailed tutorial. regard thank you all so much


Its not customizable. You have to dig into code.


Thank for reply, but may i know it should be create a new file to handler this situation or just modified the exists file to achieve my purpose for new modules that created by myself?