In case someone is looking for parts list and don't want a crash course in hose fitting thread standards:
3-Way Shower Arm Diverter for Handshower
https://www.amazon.com/dp/B0064TXMJM
G1/2 Female to GHT 3/4 adapter
https://www.amazon.com/dp/B08HQ5G5PQ
3/4" Female Thread to 1/4" OD