Creation Via Buffer Link
If you have exactly two Emacs windows in your current frame or exactly two windows visible across two Emacs frames, you can quickly create explicit link buttons from your current point (source) to the point in the other window (referent). Simply use the Link menu item, {C-h h e l}, to create a new explicit link button or to rename the one at point. Hyperbole will either use the selected region as the new button label or will prompt you for it. It will then automatically choose the link type based on the referent location and will either update the button at point or create a new one.
With more than two windows on screen, Hyperbole will prompt you to choose the referent window and its associated point to which to link. If the Ace Window package is installed and active, this will be used to choose the window via keyboard; otherwise, you will be prompted to select it by mouse.