How to Add a Filter By field to a Report

Question

Hello, I am running Apex 3.x and I currently have in production, a standard report page with the following columns:
Grant#, Grant Name, Project #, Project Name, Project Fiscal Year, Task #, Task Name
A grant can have many projects, and a project can have many tasks.
I have been asked to add a "Filter By:" field acting as a select List , with just these values: Show All, Show Projects and Tasks, Show Projects
If "Show All" is selected, the report remains the same and displays all the column headings and data for all the fields above.
If "Show Projects and Tasks" is selected, I am to refresh the page, and only show data (and column headings) for Project #, Project Name, Project Fiscal Year, Task #, Task Name.
If "Show Projects" is selected, I am to refresh the page, and only show data (and column headings) for Project #, Project Name, Project Fiscal Year
Could you please assist in directing me on how I can go about hiding these other columns and data if "Show All" is not selected.
Many thanks,
Laura

Answer 1

Create a select list with those 3 values ( and make it a select with submit ), then in your report attributes, go to the conditional columns you have and set the condition accordingly, ex: for example:
column Task # >> edit >> condition >> PLSQL expression
:PX_FILTER != 'Show Projects'
Where PX_FILTER is the new select list that you will create....
Hope this helps,
Sam