In certain contexts, field names may be referenced from within a filter string.
In almost all situations, there is a source (or context) form where you can access fields like so:
This can be within a more complex expression:
[Date] < CURRENT_DATE AND [Score] > 5
In that example, both ‘Date’ and ‘Score’ are fields in the data source form.
In several circumstances, within the context of a record, a ‘local’ field can be referenced by using the prefix [Local].
[Local].[Filter Field on Current Form]
This can be used with a source field, e.g.
[Business Unit] = [Local].[Business Unit]
This also could be a multi-select dropdown, which can be used like so:
[Business Unit] IN ARRAY([Local].[Business Unit Multiselect])
A third type of reference may be used in the context of a Step within a Stepping Expression.
STEP TO [Contract] ON [To].[Originator]=[Username] GET COUNT(1)
All [To] prefixed references are in the context of the target of the current step. In this case that is the ‘Contract’ form.