Delim: Omit columns

df3 |> 
  separate_wider_delim(
    x, ".",
    names = c("code", NA, "year")
  )

## # A tibble: 3 × 2
##   code  year 
##   <chr> <chr>
## 1 a10   2022 
## 2 b10   2011 
## 3 e15   2015