Ah, your data is a rating from various sources, all in one list type field, and you want to break them out to make use of them.
Could you just confirm, do you want the results (all the numbers) in one List type field as per my example? Or do you want one number in each of a series of fields, as per your image?
I would bet that Brian (not me!) could write an Expression to not only pull out the numbers for you, but also save them into the correct MC field. i.e. Read both the source of the rating and the number, then write the number to the corresponding MC field. That would mean that you need a custom field for every source though, plus a catch-all field for unknown sources. But that just adds to the challenge, right?
So rather than splitting the numbers out into "First Value", "Second Value". etc., write them out to the correct field as per the source.
However, that seems like a fair bit of work and processing. It may slow down MC Views quite a bit. Perhaps you should explain how you get the contents of the "AllMusic" field, which contains ratings from various source, and what your end goal is. For example, do you want to calculate an average rating across known sources, or do you really want one field per source? Are you going to apply these results to a View to select music to play?
Because there may be a better to achieve the end goal.