Subfield() is a great function for splitting a long string into seperate fields. You can use this to split out a date or anything where you have a common delimeter in a string.
For example. If you have the string
field name: TextString
line 1: Big_Frogs_Are_Yummy
You may want to split this out into 4 seperate fields.
subfield(TextString, '_', 1) as FirstWord,
subfield(TextString, '_', 2) as SecondWord,
subfield(TextString, '_', 3) as ThirdWord,
In this example the delimiter is ‘_’ as that is what splits up the words. The number is the position you want to take.
So the above will output the following for your new fields
FirstWord = Big
SecondWord = Frogs
ThirdWord = Are
SubField(text, delimiter[, field_no ])