The phrase "similar functionality" means that two things have the same or very similar capabilities, features, or purpose. It suggests that these things can perform similar tasks or fulfill similar needs. Full definition
It offered similar functionality for parks and other points - of - interest categories. (cnet.com)
Apps with similar functionality should have a similar option, so be sure to check through the settings menus in all of your cloud - based and streaming music or video apps. (android.gadgethacks.com)
I've had similar functionality for months where where I can see all of the back and forth I've had with a specific person. (onlinedatingpost.com)