User Filter Glitch

User Filter Glitch

I am developing a chart where I need the user to be able to filter by month.  No problem, I've added that filter, BUT unfortunately when the user selects "All" the filter only grabs the data that is similar in each month, rather than pulling all of the data than filtering.

For example.

I have my chart build to show impressions by keyword.  Then I have user filter's placed for Brand, Campaign, Ad Group, Impressions (Top 5, Top 10, Top 25).  This works great when only one month is pulled at a time as it shows me the Top 5, Top 10, Top 25 for each of the months. 

What I don't understand is why when I place the filter on "all" it doesn't look at the entire table to select the Top 5, Top 10, Top 25 for display.  It's only showing the Top 5 or Top 10 or Top 25 that both August and September have in common.

Please help.

Jamie