I have to admit I am a bit confused by this question.
Most strata insurance has a built-in insurance for the strata committee and office bearers.
Many exclude possible areas of legal issues, such as defamation. Strata law allows for committee members acting in good faith to make mistakes without being unduly penalised.
So, I have to ask, what is it that your office-bearers (Chair, secretary and treasurer) are planning to do that would require additional insurance?