In the Field Settings, you can see the option to "Conditionally Update Values." This allows you to select the option to "Assign When" or "Do Not Assign When" so that you can customise whether or not a field is populated based upon another field.
When using this function, you can opt to create your condition on several choices including blank, not blank, equal to, not equal to, less than, more than and matches the regex.
If you wish to apply a field based on if the incoming amount is greater than or less than a specified amount, for example, if you only want to assign a Letter Code to gifts over a set amount:
If you want to apply multiple Letter Codes based on the incoming value, this would require a different approach. Instead of using Conditional Update Values, you would apply the Amount field from the Data Source to the Letter Code field and then apply a series of Data Transformation, starting highest value to lowest value and using the Greater than/Less Than Match Type
