Even though this won't affect the "hover references", another related configurable item is @ 'Tools > Options > Languages > Application Languages > C/C++ > Context Tagging®'
"Prioritize navigation to:"
...and from the docs:
Here you can specify if you prefer to navigate directly to a symbol's definition (proc) or declaration (proto). If Prompt is selected, the Select Symbol Dialog is displayed, prompting you for both definitions and declarations. In any case, if you use Ctrl+Dot to jump to a symbol, you can cycle through the alternate symbols by pressing Ctrl+Dot repeatedly. You can step backwards through the list of matches by pressing Ctrl+Comma. However, once you reach the first match, Ctrl+Comma will then pop you back to your original location, where you were before you pressed Ctrl+Dot.
Independent of the settings for these options, in the following circumstances, SlickEdit® will jump directly to the definition or declaration.
If the cursor is on the first line of a symbol's declaration, it will jump directly to the definition, provided it is unique.
If the cursor is on the first line of a symbol's definition, it will jump directly to the declaration, provided it is unique.
This behavior is particularly convenient for C++ programmers to navigate from a function to its prototype and vice versa. See Symbol Navigation for more information about navigating through your code.