- Create a new Select property and add the new tag to that, then assign it to all of the entries that require it.
- Create a formula property and add the following:
prop("Existing Tags Property Name") + "," + prop("New Tag Property Name")— this will output a comma-separated list of the existing tags with the new tag added to the end.
- Click and drag to select all of the cells in the formula column, then copy them.
- Change the existing Multi-select tag property to a Text property. This will convert it to a comma-separated list of tags.
- Click and drag to select all the cells in the tag column, then paste.
- Change the tag Text property back to a Multi-select one.