Delete previous markets on google maps

Ok I have tried what is shown in the screenshot and it does not seem to work, Here is what I have:

All I want it to do is remove the previous markers in a way that there is only one marker on the screen at a time, that way the app does not get filled up with markers.

Many thanks, Levi

Please don’t create new topics for the same issue. It makes it very hard to help you and have any continuity in the forums. You can add more details here: