Vertical divider between sub menu columns

Hi everyone,

Does anyone know how to get vertical column dividers for their grid layout sub menu?

Currently, I have added in a right side border for the 2nd and 3rd level menu items but they only reach as far as the links in each column. Ideally they will all be the same length and centered in between each column. Just can’t seem to find a solution!!!

This is the website for reference https://robertslegal.com.au/

Thank you!

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