Normally, we expose report via the customized portal page based on user or user group. in case when end user want to run report with parameters to be specified on the fly, some technical challenges are presented to resolve. The main reason is that report will run automatically as soon as portal page displays. First of all, in case when your report has default parameters, report will run based on default parameters without even show prompt page at all. Secondly, when finished report rendering, it is impassible to give user the opportunity to import parameters again.
Use portlet with navigatorThe best way to handle it is to create a new directory for reports to be run for end users, and then create a portal page with navigator, where navigator points to the directory.
In this case, business user uses Cognos report in a similar way as developers. He or she can run report whatever wanted
Use portlett with muti-page dashboardIn this case, you need to make at least one parameter required, otherwise the prompt page will not even appear at all.
The main problem is that user won’t give the second opportunity to specify parameter
Use global filtersIn order to resolve the issue above, we need to give business user to select parameters. The solution is to separate prompt page from main pages, and then use global filter to pass parameters to main page.
Please see old blog How to make global filter work with multi pages for detail reference.