Not every Xpath is working - which version does KAR using?

I wonder which version of Xpath Katalon is using because if I try something like:

//div[5]/div//div/span

or

//(div/div[contains(@class,‘something’)])[3]

command is changing to green but it’s not work. If i find this element with something like this:

//div/div/ul/li[2]

without using “//” in the middle or “(element)[number]” it works properly.