Select Face Loop
The Select Face Loop action selects a face loop from each selected face.
ProBuilder only considers faces part of a loop if they are quads (contain exactly four sides). Face loops generally run along the Z-axis, while face rings generally run along the X-axis.
This action is only available in face mode.
You can use this action with the Alt/Opt+L shortcut, or from the ProBuilder menu (Tools > ProBuilder > Selection > Select Loop).