The legacy/ locations are always pointing to the data of the currently active user. Let me first point to a few related questions/answers explicitly dealing with those multi-user storage issues for some background:

• Why did /sdcard/ turn into /sdcard/0/ with 4.2?
• Confusing internal memory folder structure

So to find the files of the secondary user:

• list the sub-directories of /data/media and /storage/emulated
• restrict your search to sub-directories whose names are simply "numbers"
• the 0 candidates belong to the owner, higher numbers are of secondary users
• external storage is something different: /sdcard/0 points to the internal sdcard, while /sdcard/1 should be the external (if available). Similarly for storage attached via OTG

Remember you might need to be root to access data of a user other than the one currently active on the device.

Also see:

• Android Folder Hierarchy
• our tag-wikis for file-system and files

The legacy/ locations are always pointing to the data of the currently active user. Let me first point to a few related questions/answers explicitly dealing with those multi-user storage issues for some background:

• Why did /sdcard/ turn into /sdcard/0/ with 4.2?
• Confusing internal memory folder structure

So to find the files of the secondary user:

• list the sub-directories of /data/media and /storage/emulated
• restrict your search to sub-directories whose names are simply "numbers"
• the 0 candidates belong to the owner, higher numbers are of secondary users
• external storage is something different: /sdcard/0 points to the internal sdcard, while /sdcard/1 should be the external (if available). Similarly for storage attached via OTG

Remember you might need to be root to access data of a user other than the one currently active on the device.

Also see:

• Android Folder Hierarchy
• our tag-wikis for file-system and files