@Override
    public String getValue(ReferenceAddressPair rowObject, Settings settings, Program pgm, 
	    ServiceProvider serviceProvider) 
	throws IllegalArgumentException {
		Function fromFunction = getFunction(rowObject, pgm);
		return (fromFunction != null) ? fromFunction.toString() : null;
	}
This table field displays the name of the function containing the from address for the reference.
Ghidra/Features/Base/src/main/java/ghidra/util/table/field/ReferenceFromFunctionTableColumn.java