Can I use Lunala GX's "Psychic Transfer" Ability to move a {P} energy back to where I got it from on the same turn? How about if I move it between the same two Pokemon several times in a row?
You have to advance the game state with your actions. If your Psychic Transfers are mindless, then you are not advancing the game state and it could result in a penalty.
Source: Ultra Prism FAQ (2018-01-19), TPCi Rules Team (2018-02-01)

Relevant cards

Note: All applicable cards may not be listed below.
SM5_172