Storing multiple values with a device state command

If I have multiple values to be stored into an attribute of a device, is that possible? or will it only store the most recent device:state command values. or is there another way to store multiple values into an attribute of a device?

For example. if i have a tag as a device and the tag sees 2 different devices and i want the tag to record both those device names under the attribute “BDmac” so when i pull up BDmac of that tag, i want to see that it has 2 devices it sees.

Thank you in advance!

Attributes are always reported to one device at a time. It is not possible to report an attribute value to multiple devices simultaneously using a tag.