Can I define multiple system messages in the playground?

Is it possible to define multiple system messages in the OpenAI Playground?

I want to compose a history of messages similar to:
System, Assistant, User, System, Assistant, …

I can do this via the API and also e.g. via the Langsmith Playground, but it seems to be impossible to add System messages to the list of messages in the OpenAI Platform Playground - beyond the very first, default System message.

Thank you for your help!