Hey there - it would be helpful to learn a little more about the specifics you are looking for.
But, as I understand it, you are wanting to contact those who have booked time with you before and request a review?
Depending on how long it has been (thus the "depth" of the relationship), you can message them here on Clarity. If you have the time and desire, you can also seek them out on LinkedIn and connect with them there to request a review.
I hope this helps!
Keep in mind - your goal should be to always strengthen the relationship mutually, not seek them out (or stalk them) for your own benefit.
All the best,