The top 3 images are from my UMG Widget Designer Section where I did an Xbox controller and the buttons highlight when pressed. I just remembered I could not find a way to dynamically change the image so I had to put an image on top for the highlighted version of the button and then dynamically set the visibility. To layer the buttons (Image on far left top) I had to use a Scale Box, Then an Overlay Box and the Place in the Images. Put the image with Lock on top of one without. Then When You read your boolean Variable from the array, if true you could set the image to Hidden, and if false set image to Visible along with disabling user input on the button.
You will need to do some homework and look up tutorial videos on creating save game files/information to be able to save the variable info for the levels that are unlocked. Here is link to Tutorial for that -
