Thanks for this code, it works great on it's own. Here is my use case:
I have a select field with the following values ('studio', '1 bed', '2 beds', '3 beds',...'10 beds'. I am using Gruid Builder WP to create facets. I need my facets for Bedrooms to be studio, 1 bed, 2 beds, 3 beds, 4 beds, and 5+ beds. My thought is using a checkbox list with those values which I will populate before save based on the number of beds chosen in my select field. Then I can just create a facet based off the checkbox list. How do I use the add_post_meta function with rwmb_before_save_post? add_post_meta requires a post ID, but I'm not sure how to retrieve that when utilizing the rwmb_before_save_post... Sorry for the noobish questions.
