I have a grouped dataset that contains data that can be repeated at multiple instances within the same group. I need to count the total number of repeated values for each instance that occurs within the same group. Here is a toy set that shows my example:

structure(list(Group = c(1, 1, 1, 2, 2, 2, 2, 2, 3, 3, 3, 3, 
3), ID = c("non repeating", "repeating", "repeating", "repeating", 
"repeating", "non repeating", "repeating", "repeating", "non repeating", 
"repeating", "repeating", "repeating", "non repeating")), class = c("tbl_df", 
"tbl", "data.frame"), row.names = c(NA, -13L))

My desired output, because I need to filter these later. would be the following:

What I’ve tried so far is the following:

ex <-
  ex_data %>%
  group_by(Group) %>%
  mutate(
    Value = case_when(
      ID == lag(ID) ~
        1,
      TRUE ~ 0
    )
  ) %>%
  mutate(
    Value = case_when(
      ID == lead(ID) ~
        1,
      TRUE ~ Value
    )
  ) %>%
  group_by(ID, .add = T) %>%
  mutate(count = sum(Value))

This produces the following, and not what I’m hoping to get as the values are being summed across each group instead of each group and ID

What am I doing wring here?