If you transferred his data via USB or file manager:
Connect your phone to your laptop via USB.
Browse to DCIM/, Pictures/, and Movies/ folders.
Sort files by Date Modified or Date Created.
If you remember roughly when your dad's data was copied over (e.g., last week), look for files added around that date.
Move them into a new folder on your PC: e.g., Dad_Images and Dad_Videos.
Tip: If his files were in a particular folder before (like WhatsApp, Camera, or a custom folder like DadPhoneBackup), they'll likely still be grouped in folders — this helps speed up sorting.
Optional: Use EXIF data to sort more precisely
Use a tool like ExifTool or a photo manager like XnView MP or FastStone Image Viewer to sort images/videos by Device Name or Original Date Taken.
This way you can distinguish files taken by your dad’s old phone (e.g., "Samsung SM-A125F") from your own device (e.g., "Pixel 6").
Once the files are sorted on your PC:
Connect your dad’s new phone to the PC.
Create folders like:
DCIM/Camera/
Or a custom one like Dad_Backup_2025
Copy only your dad’s files (from the folders you created in Step 1) into these directories.
His phone’s Gallery app should pick them up automatically.
Hope this will be your help.