When you invoke Basic Completion &shortcut:CodeCompletion;, GoLand suggests the choices that are reachable from the current caret position. Press &shortcut:CodeCompletion; again to find all the suitable functions that accept the value as the first argument.
For example, if you type "/hello/world". and then press &shortcut:CodeCompletion; two times, you will see a list of functions that accept a string as the first argument.