It would be better if there is ability in qlik reporting services to generate reports with dynamic filter selection from frontend so user can trigger a reporting Service from frontend button along with current selections.
I agree. The Reporting Service Add Selection block is too limited especially with dates as there no option to filter by greater / less than, and to select a range an array has to be created and applied to the field.
There is roadmap consideration for on-demand of automations triggering Qlik Reporting Service reports. The reporting roadmap is also evaluating on-demand as part of more advance authoring report capabilities.