In more recent versions of FL Studio, users can now group notes by color in the piano roll. To do this, double-click on the desired note and then click on the color indicator. You will then be greeted with various color options from which you can choose to group the note to.  Grouping notes within a MIDI pattern can be a great way of organizing a complex sequence. It can also allow users to make more precise note slides for single notes out of a chord.