No. There is no action in Mp3tag, but a "Tag Sources" dialog, which may help.
You can use the dialog "Mp3tag/Tag Sources/freedb (Local)" and push the radio button "determine from inserted Audio CD". One of the following dialog windows displays the calculated DISCID.
The DISCID then should be stored into the tag-field DISCID as given in the dialog along with the other track related data.
The DISCID value can also be copied to the clipboard, without permitting the dialog, and can be copied to anywhere else.
To calculate a proper DISCID or CDDBID you need the original CD (physical medium or disk image).