Complex sentence: The idea of establishing the organization took shape after Deri witnessed a protest of the Boycott, Divestment and Sanctions movement in Ireland where spokesmen based their arguments against Israel on materials from Israeli organizations, such as "Breaking the Silence".
Split into simpler sentences: The idea of establishing the organization took shape after Deri witnessed a protest of the Boycott, Divestment and Sanctions movement in Ireland. In this movement, spokesmen based their arguments against Israel on material from Israeli organizations, such as "Breaking the Silence".