Using WRKOBJ with OBJTYPE(*MENU) is a valid answer. Of course, it requires that the objects are all created as menu objects.
Any application can create a display file and program that looks and behaves like a *MENU object. But if it’s not created as a *MENU, it’s just another display file and program.
Be sure that you know what all of the “menus” actually are.
We have our custom menus set up as actual *menu objects.
Our software provider has their menus all coded in CLLE.
The main reason for them being a program is for security and menu option access.
My suggestion is to start with the *menu objects like suggested.
If a menu does not show up on your list that you expect then look for it with type *all.
WRKOBJ OBJ(*ALL/MYMENU) OBJTYPE(*ALL)