Split column content into multiple columns

Screenshots are considered a bad practice here since we cant select and copy code from them, post formated code instead. Here is how to do it

I can't be sure this code is going to work for you since you are not providing a reproducible example and I'm not willing to download a file from that source.

library(tidyverse)

dat %>% 
    group_by(`Reaction List PT`) %>% 
    summarise(n = n()) %>% 
    mutate(`Reaction List PT` = str_replace(`Reaction List PT`, "\\(", "- "),
           `Reaction List PT` = str_remove(`Reaction List PT`, "\\),")) %>% 
    separate(`Reaction List PT`,
             into = c("Reaction_List_PT", "Duration",
                      "Outcome", "Seriousness_criteria"),
             sep = " - ")

Since you are a newbie I strongly encourage you to learn how to ask your questions providing a proper REPRoducible EXample (reprex) illustrating your issue. This is not only the most effective way to ask for help it is also the most polite.