You can detect clicking on the world map by putting a clear widget button on top of it, and then detecting the cursor location on click. (remember to zero out the alpha on all the button images Normal, Highlight, Pressed, etc.) Then to drag you’ll need to use the Drag and Drop system built-in to Unreal. It has parameters to clip your object within the bounds of the map, drag the object around responsively, and then detect when it is dropped. There is a problem you’ll need to work around to have the drag update in real-time if your mini-map is not a widget, I don’t imagine it isn’t, but heads up tracing into the world on drag is a pain due to input state. This tutorial is goofy named, but seems the best explanation I’ve found on this system. Beyond that it sounds like you have the difficult stuff figured out, translating from mini-map space to world space and accurate HUD waypoints is the tricky bit.
