Looker Expression assistance

[Malandrino1420]

Hi -- I am new to Looker and am wondering if someone knows of an expression. I need to create a new column based off "Department Name" that takes just the first 3 characters aka the dept number. I tried using "left_text" but not sure that i used correctly seeing that i get an error message that it's either incomplete or an unknown constant. any help would be greatly appreciated.

[RobHendriks]

Thank you for the question. Here is what I'd suggest you try

SUBSTR([Department Name] 1, 3)

https://support.google.com/looker-studio/answer/7583225?hl=en