How would I count these groupings to a metronome? What is the correct way to interpret groupings such as these? Note: Time signature for this is 12/8.
Well if you actually do want to count that and play it accurately, you'll need to divide the count up. The 10-plet in the start of your example could for example be split into a 6+4 count, from looking at what you play there, or even 2+2+2+4. Also if you have no experience with quintuplets, septuplets and so on, learn those first to get a feel for larger tuplets.