Hi @AntonioRojasR,
You can do this by do the placing one where you want on a sheet and using the Viewport.GetBoxCentre (Py) code supplied in this post above…
Just copy the pyrhon code into a fresh and clean python node and plug in your legend viewport.
Or you can use the place multiple views on sheet node found in this thread and use sliders to place one where you want it.
Hope this helps.
Cheers,
Dan