After "OnLenghtChange_" events name and array variable must be the same.
Events name are case sensitive.
Steps:
Click ADD NEW button. Select blueprint.
Add an Actor Blueprint Class. Open it.
Open event graph.
Add ZD ACTOR component.
Add a new variable from the Variables section under My Blueprint Tab. Make it public and change it as array.
Add a new "CustomEvent". Right click and write "Add Custom Event".
Name must be "OnLengthChanged_MyBooleanArray". (As you can see variable name and event name after "OnLengthChanged_" is same.)
Add nodes as shown in below image.
When we add a new value into "MyBooleanVariable" array the events will print length of array. This is the basic code for understanding how its working.
Add ActorBlueprint to scene.
Click PLAY button and open Reality Setup.
Select MyActorBP node.
.As you can see actor blueprint appears in Reality Setup. Thanks to ZD ACTOR component.
Array variable also appears in properties tab of MyActorBP. Because we made it public variable.