Field values can be exchanged between fields in two column as follows
If you have selected some fields in two separate columns this swaps the fields in one column with the fields in another
If you have selected some fields in two separate columns, this option will copy the contents of the fields in the right column into the start of the fields in the left column (separated by a space character)
If you have selected some fields in two separate columns, this option will copy the contents of the fields in the left column into the start of the fields in the right column (separated by a space character)
If you have selected some fields in two separate columns, this option will copy the contents of the fields in the right column into the end of the fields in the left column.
If you have selected some fields in two separate columns, this option will copy the contents of the fields in the left column into the end of the fields in the right column.
If you have selected some fields in the track no column, this option renumber the fields starting from the value of the first field (based on the current sort order), or starting from one if the first field has no value. The renumbering is based on the current order of the files, the numbering takes into account your Track No Preferences