I mocked up some code based on the example Zachary gave and some code I have used for looping through a set of fields in a collection/table. I have not tested it but it may work with tables or collections.

If this works it could be rewritten so the field id is passed in then it could be used for multiple fields on the same form.

const resetFieldID = 2;

function resetFunctionFields() {
  let resetFields;
  let currIndex = 0;
  let currOldValue;
  
  resetFields = LFForm.findFieldsByFieldId(resetFieldID); 
  
  /* loop through all fields */
  resetFields.forEach(async function (currField) {

    currOldValue = LFForm.getFieldValues(currField);
    
    LFForm.setFieldValues({fieldId: resetFieldID, index: currIndex}, "")
      .then(() => {
      LFForm.setFieldValues({fieldId: resetFieldID, index: currIndex}, currOldValue)
    });
    
    currIndex++; 
  }); 

};

/* on load */
resetFunctionFields();