This demonstrates the process for creating and calling a custom event in a Level Sequence’s Director Blueprint. The custom event in this example overrides the material assignment on all static mesh actors. The level sequencer is incredibly powerful and can be used to dynamically modify any parameter of any actor. You can add them directly to the sequencer or gather them procedurally, as in this example.
https://dev.epicgames.com/community/learning/tutorials/yyX3/unreal-engine-director-blueprint-example