private Function getFunction(ReferenceAddressPair rowObject, Program pgm) 
	        throws IllegalArgumentException {
		Address fromAddress = getFromAddress(rowObject);
		if (fromAddress != null) {
			return pgm.getFunctionManager().getFunctionContaining(fromAddress);
		}
		return 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