Hey @dhanu3 , yes as you correctly point out that won't work in Employee Center because the Header Menu items are hard coded into the widget itself. In order to rename items in that header, you unfortunately need to edit the widget itself, by making a clone OOTB.
While it's not advised, the only other alternative is using our translation tool. Which personally I can't say I'm a big fan of doing since that is not what it's intended purpose is.
