Gym Recovery Issues

Ive been traveling a lot and cant seem to remember which gym I have one of my Pokémon at. Its been bout 2 months now. Would like to level him up but cant. Could you please introduce a way for us to either see which gyms are Pokémon are located at. Or put in a function that would allow us from our collection menu to retrieve our Pokémon back.

SouthernLifeStyles about Pokémon GO, v1.31.0