yes it is possible. i havent worked with drop menus so ill speak as if it were buttons but should be the same. basically you just need a on click event which calls the move to, you will also need a reference to where you want to move. this is why you cant find the character as you cant get a reference like you could in the level bp.
the easiest way to implement all this for your case would be to create the widget from the level bp and assign a variable when created whos value is the location or actor you want. to do this, create your widget and add the move to script, then create a variable array named targetactors. now in the level bp you need a script which creates the widget and adds it to the viewport. now from the create widget node drag off the blue output pin and search for set targetactors to get the variable. now you can just drag in a a reference from the level and make the destinations into an array.
below is a example of how this could be done. you could also make the destinations more dynamic, being selected based on criteria at run time but thats a bit more complex. this should show you the basics of how to get it done.
