Learning > presentation > hierarchies > E C Expressions Edit this page Hierarchies-related ECExpressions Rule Condition Child node rules have a condition ECExpression property which defines which rules should be applied for which parent nodes. The following ECExpression symbols are available there: Symbol Type Value ParentNode NavNode context The parent NavNode expression context. Additionally, Ruleset variable symbols are available as well. Instance Filter ECExpressions that are specified in instanceFilter specification properties are converted to ECSQL WHERE clause, so they have some limitations - ony a subset of all the ECExpression symbols are available. The below table lists all of them: Symbol Type Value parent ECInstance context The parent ECInstance expression context. this ECInstance context ECInstance expression context of the ECInstance that's currently being handled. Additionally, Ruleset variable symbols are available as well. Specification Symbols available in expressions evaluated at each node's level (e.g. hideExpression): Symbol Type Value ThisNode Node context NavNode expression context of the ECInstance that's currently being handled. this ECInstance context ECInstance expression context of the ECInstance that's currently being handled. Additionally, User Settings symbols are available as well. Last Updated: 15 June, 2021