There are several ways.
One way to combine fields is to fill some other field with a rule. For example, if the artist is "The Beatles" and the album is "Abbey Road" you can write or paste this rule:
=[Artist] - [Album] in a third field for getting this value:
The Beatles - Abbey Road. As always, you can tag a bunch of files by selecting them all first.
Another way is to create a "calculated" custom field with a similar rule. This field would be dynamically updated. For example, if the rule is
[Artist] - [Album] and the example album name is changed from "Abbey Road" to "Let It Be" the value of this calculated field will automatically change to
The Beatles - Let It Be.
It is also possible to use the filename for combining fields. I have explaned that in these old threads:
http://yabb.jriver.com/interact/index.php?topic=28424.msg196950#msg196950http://yabb.jriver.com/interact/index.php?topic=28764.msg199070#msg199070EDIT
I forgot to mention that the place for adding custom library fieds has changed. In MC12 you can add a calculated field here:
Options > Library & Folders > User Library Fields > Add Field... > Data, Calculated data, Templete: [write the rule here]. After the library field is created you can add it to your view schemes as a new column and to Action Window > Tag.