Using this function (Annotation > Paste annotation here or press CTRL+SHIFT+V) you can copy an existing annotation to any tier and time you want. (Of course the tier still has to belong to the same tier type). The copy will be placed on the position of the crosshair on the active tier.

Right click somewhere in the timeline viewer and select Paste annotation here from the context menu to copy the annotation to the position of the mouse cursor – both the tier and the time position.