Converting coordinates from 2d

So me again with stupid questions. How can i convert verctical box coordinates to mouse cursor/actor position. I need to be able to show/hide this menu at the position of cursor/actor that was clicked.

Yeah thx i know about this, but, ok i’ve got something. Now menu(vertical box) appears almost at the cursor position, but when i move cursor to the right side - menu moves to the left, when i move it down - menu moves up? I know my skills are :frowning:

that’s some weird stuff
why do you get mouse position on screen
convert it to world space and then convert it back into position on screen?