One feature of FileMaker Pro that impresses new customers is self-building value lists, which are value lists based on the contents of a single field. There is something mysterious and magical about a list updating itself from the data the user has already entered. But, have you ever found yourself creating essentially the same value list for two or more separate but similar fields?
Take, for example, a field <home city> for a contact's home address and a field <work city> for a contact's work address. With the following technique, you can have a self-building value list that includes all the values from both <city> fields show up in the same value list. This approach is useful because a user doesn't have to enter the same value twice, as he would with two separate value lists, and both fields display a more comprehensive choice based upon what he has already entered in similar fields.
To create a combined list, simply create an additional calculation field <citylist> and combine the two fields using the calculation:
Home City & "¶" & Work City
Create a new value list called "City" and specify this calculation field's values to be used to generate the multi-field list. That's it!
A few notes: Do not turn off indexing. FileMaker Pro must index fields used in value lists. FileMaker Pro uses indexed carriage return-separated text to determine the values in the list. The pilcrow symbol (¶) I used in the calculation creates a carriage return so each field is on its own line. You can add as many fields as you want to your calculation, provided that each additional field is separated by a carriage return using the pilcrow symbol and all your source fields are in the same table.