Bombs fall in a line, at the set setting, centered around the pipper.
So with 3 bombs in the profile, 1 will fall at the pipper location, 1 will drop 75' long, the other will drop 75'ft short.
Same for CBU's, with the addition that the canisters will open at the configured altitude and disperse the sub munitions.
To know the footprint of each canister, you can use this reference: http://www.476vfightergroup.com/downloads.php?do=file&id=73
You have to keep pressing the button until all weapons are released.