Batch Actions > Add to Selected Asset
This item is available from the Batch Actions Menu when the asset collection is editable. It opens a dialog in which you can select one of the relationships that are available for the asset that is currently (globally) selected on the Form Panel.
Once you have picked one of these relationships, you can use the Preview button to check that it is sensible to add the values from the batch operation to the selected asset, or whether there would be constraint violations. You can then apply the change and add all values to that relationship.
Further Reading on Batch Actions Menu
Further Reading on TopBraid