This paper introduces Ethics Pathways, a design activity aimed at understanding HCI and design researchers' ethics engagements and flows during their research process. Despite a strong ethical commitment in these fields, challenges persist in grasping the complexity of researchers' engagement with ethics -- practices conducted to operationalize ethics -- in situated institutional contexts. Ethics Pathways, developed through six playtesting sessions, offers a design approach to understanding the complexities of researchers' past ethics engagements in their work. This activity involves four main tasks: recalling ethical incidents; describing stakeholders involved in the situation; recounting their actions or speculative alternatives; and reflection and emotion walk-through. The paper reflects on the role of design decisions and facilitation strategies in achieving these goals. The design activity contributes to the discourse on ethical HCI research by conceptualizing ethics engagement as a part of ongoing research processing, highlighting connections between individual affective experiences, social interactions across power differences, and institutional goals.