In R files, code is usually divided into named sections that can be accessed in RStudio with a menu similar to that from Ctrl + R in sublime. In order for code to mark its section, it needs to have the following:
# <section1 name> ----
<code>
...
# <section2 name> ----
<more code>
...
If I open an R file with sublime and press Ctrl + R , it doesn’t show those selectable sections.