Toriaviplean,
Select the bullets placeholder by clicking on the edge, apply an entrance
effect using the custom animation task pane wipe from left for instance. If
all has gone will there should be a different number next to each bullet. If
not double click the effect in the pane, choose last tab and in the group
by section choose the level you want to group by.
For more info have a look here: http://www.pptfaq.com/FAQ00581.htm