How to get the top 10 value in BIRT

Migrateduser

<p>I have a trouble that I need to get the top 10 busiest stations, right now, I have these columns (number of buses, datetime, station name). Now, I can dynamically change the time range based on user's selection. But, the BIRT just show all the stations' name in one chart. How can I get the top 10 stations' name? I tried to add filter in my chart, but after I added it, it only showed one station name. Can anyone help me solve my problem? (In my chart, the X-axis is the station name, and Y-axis is the number of buses)</p>