This study proposes a framework for examining hashtagged content on social media, which captures how specific issue frames (i.e. hashtags) contribute to navigable structures. We introduce ‘interwoven multimodal discourse’ as a pluralist alternative to the widely applied unitary approach in which trending hashtags serve as primary sites of analysis. The study argues that ‘interweaving’ of social media discourse takes place through practices such as hashtag colocation, which result in ambient and navigable structures. Analysis of hashtag colocation networks can serve as an approach for mapping ambient affiliations accessible through such structures. We analyse a hashtag colocation network constructed using a sample of 1100 Instagram posts related to climate change uploaded during the United Nations Climate Change Conference 2021 (COP26) held in Glasgow to demonstrate two structural properties of interwoven discourse on Instagram: (1) hashtags contribute to multiple thematic clusters and (2) micro-level hashtags representing secondary topics are nested within larger thematic clusters.