Data-driven category to differenciate cameras by UI

[mastodon]

I have a lot a pictures, that are taken by the same camera modell, but a different piece. And if I would know, wich one is used for that photo, that would know help me where it was taken etc.
Is it possible to add a data driven category to embedded Camera Name category, that differentiate the modell by uniuqe id-s? I know, that serial number and other UI-s are not always soterd, and not in the same XMP tag. 
Now I like to have it for the Panasonic tag "Internal Serial Number", that looks like: XEL1610050195 (date:2016-10-05. sn: 0195). But mybe it is possible to create a general solution for UI-s.

[Mario]

When I understand your question correctly, this is very easy to do:

1a. Figure out which tag to use
1b. If your cameras use different tags for their id/serial number, create a variable that uses hasvalue / default to 'probe' all 
available tags for one with a value. See hasvalue

2. Use the tag or variable from above as the second level for the Camera Name data-driven category.

This uses the camera name as shown in your screen shot, and creates a serial number / id level below tat.