If you converted a numeric variable to a group variable, whatever be its label, you're loosing information. You cannot go back to original information only from the newly available information.
In the first step, you could do something like this:
data_set$grouped_value <- cut(data_set$numeric_value, vector_of_breaks, labels = vector_of_labels)
Hope this helps.
@TyeGalloway, did you try my solution? It'll do what you want.
mutate isn't magic. It won't be able to get information which is lost. But if you are tidyverse only person, here's the equivalent line of my above code with mutate and pipe operator:
data_set %>%
mutate(grouped_value = cut(numeric_value, vector_of_breaks, labels = vector_of_labels))
And, this is not correct totally.
It depends on the name you use. If you use same name, it'll override. The problem with your code in original problem is that only.