First off:
Rules - cycle.
NOTE: with rules you pretty much need to get it right the first time, cuz if you find you need to add a higher level rule, then you cannot just move child dims into it, you'll need to do them over.
Took me a while to figure this out, but to make this work you need a parent dimension and then x child dims for each item you want cycled.
i.e.: let's say you have bass gtr samples with each note having an up and down pick sample, and you want to alternately play the up/down samples.
Create two layers called uppick and downpick and place the samples accordingly.
In rules create a parent dim and choose 'cycle' as the rule.
Create two child dims and for each child choose one of the above layers
You're now good to go, and you can check it's working by choosing a sample in the sample edit window and play the its key. Every other note the "insertion point" will move across the sample as its played.
I can't get "Note Duration" & "Playing Speed" to work (or even figure out what they're supposed to do

Modulation/Mapping would also be a good thing to add here.