Tatu is correct. I don’t know of a way in RF, or in SeleniumLibrary to be exact since it sounds like you are talking about web app tests automation that you can provide multiple different locators for the same element and have the automation try, say all 3, for a given button. I’ve heard of other tools where you can do something like that. Personally I dislike the approach.
The best you could do is how you write your locators in such a way that they are not so tight and hardcoded and brittle. For example, don’t use text() = ‘some fixed text’ but instead use contains. Or just don’t cue off of text or labels but use other HTML attributes to construct your locators.
XPath does have a way to specify OR clauses for your locators so that could gain you some flexibility but it’s rather advanced stuff and if you are hoping to do that for all of your locators it’s going to take you forever!
Making the automated test script “smart” enough, or I prefer to way flexible enough is really up to you the author of the script, really the author of the locators/selectors.