Sharing photos from two different libraries

As per this article https://support.apple.com/en-in/HT204414

If you have multiple photo libraries on your Mac, you can choose one to be the System Photo Library. The System Photo Library is the only library that can be used with iCloud Photos, Shared Albums, and My Photo Stream.

So , you have to combine the two libraries https://discussions.apple.com/thread/8536957

And then share photos through albums with different device https://support.apple.com/en-in/guide/icloud/mmc0cd7e99/icloud

https://support.apple.com/en-in/guide/photos/pht884a8908/4.0/mac/10.14

How are you sharing the photos? Via a Shared Album? You could have a 3rd library just for sharing and make that the System Photo Library. Then with the paid version of PowerPhotos you can copy albums of photos from both other libraries to it to be used in a shared album online.

You can also export the Photos out of the other libraries to the Desktop and then import into the System Photo Library.

OR make your personal library the system library and copy the photos from your work library to it and share. Use either the PowerPhotos or export and import method of getting the Photos into the library.